An intellectual with exceptional knowledge….

by Asmita Nandlal Rajbhar


“EXPERT” as the name suggests – someone who is exceptionally skilled and knowledgeable. An expert help is taken where in a situation the conclusion of the circumstance is not easy to determine. An expert is an aid to provide assistance to draw a concluding matter from the obscure theme. Like ways in Indian judiciary expert witness plays a role of providing assistance to the judges in a matter where a specific and detailed clarity is needed on a particular matter of fact to deliver the judgment. Hence expert witness is a person to provide aid in the form of assistance to administer justice.

Who is said to be an expert witness?

An Expert Witness is a person with knowledge or experience of a particular field or discipline beyond that to be expected of a layman. The Expert Witness give an impartial opinion to court of tribunal on particular aspects of matters within his expertise which are in dispute.

A witness is a person giving sworn evidence to a tribunal or court of law. There are basically two types of witness:

  • Witnesses of Fact who may give evidence of fact but may not normally give opinions;
  • Expert Witnesses who may give opinion evidence within their expertise and in addition evidence of facts.[1]

History of Expert Witness

The first documentary evidence of forensic expert was Autistics. He was asked to

examine the corpse of Julius Caesar to determine the cause of his death and opined

that only one of the 24 sword wounds were deadly.

Experts have been used in English courts in 14th century. Scientific expert testimony

has long been a thorn in the side of the courts, because experts are not only allowed to

explain facts, but to express opinions; even when they concern the ultimate issues at


Two hundred years ago it was still possible for an educated person to gain a

satisfactory overview of the cultural world of his own society since the dawn of

modern chemistry.[2]

Qualifications of an Expert Witness

Nowhere in Indian Evidence Act, the qualifications of an expert are mentioned

explicitly. The general qualifications are skills, training, education or experience. It is

the discretion of the court to decide the qualifications of the experts in the relevant


Pre-Requisites of Expert Evidence

There are two important conditions that are necessary to be shown……

  1. That the subject is such that expert testimony is essential.
  2. That the witness in question is really an expert.[3]

It must be proved that the witness is competent enough to give the evidence and that the fact to be proved a point of science or art of which the witness is an expert in, before the opinion of a person can be admitted in evidence.[4]

If a witness is not proved to be an expert. His opinion will become irrelevant. It must be proved that the witness is an expert. He must be examined as a witness in the court and be subjected to cross-examination.[5]

Functions of Expert Witness

The primary function of an expert witness is to express his independent expert opinion based on the information that is provided. An expert can be employed in different capacities for example at arbitrations, tribunals, and litigation.

  • Provide an independent expert opinion in their area of expertise on the subject matter in accordance with the instructions they are given. These instructions will be shown in the Expert Witness’s Report which will be seen by the other side and the Court.
  • Provide the opinion in the form of a report and/or evidence before a Court (or other tribunal) as required. The report is required as it is not usually possible for the Expert to give evidence without it.
  • Ensure the Expert’s Report provided to you contains the information required by the Court Rules. If you proceed you will have to give a copy of the report to the other side in the dispute. At that time a copy of the other side’s Expert’s Report will be given to you.
  • Comply with the specific procedure rules applicable and any Court or tribunal Orders in the case.
  • Provide truthful, impartial and independent opinions whether or not these opinions favour your case.
  • An expert witness has an overriding duty to the Court (or other tribunal). This duty supersedes any duty owed to you even though you are still responsible for paying the expert’s fees.
  • The Court expects an expert witness to be independent and impartial and will discount the evidence of one who is or is seen to be partisan.

DONTS of Expert Witness

  • Be your advocate and argue your case, nor will they find evidence or suggest what your case should consist of. It is for you or your legal representatives to advocate your case.
  • Provide any opinion beyond their specific area of expertise.
  • Accept any appointment which involves a conflict of interest.
  • Accept any appointment on terms that are conditional on the outcome of the case. Examples of these are success fees or conditional fee arrangement Conditional terms are incompatible with the expert being seen to be independent.
  • Act as a negotiator.
  • Agree contractual terms with the expert in writing before the work is started. These will include terms of payment. Many experts use standard terms.
  • Provide detailed instructions.
  • Keep the expert informed of developments in the case and of all key dates in good time.[6]

Various rules for expert opinion

  1. The first rule is of expert educational background. That means even a doctor is examined and is subjected to scrutiny and cross examination. And if his opinion and observations contained in his statement are supported, then the report can be looked at otherwise not. So even the examination of a doctor becomes essential.[7]
  2. The second test is of the exhibits and the illustrations that the expert brings with him or makes. He should not base his opinion on the basis of memory and abbreviated notes. But he should have the opinion of such a level that even if there is expert evidence of the opposite party, then also, he is able to depend his stand.
  3. The third test is of readiness to the detail his techniques and procedures. An expert should not be of skilful nature to outlining the procedures that he has followed. And he should be so confident that no qualms can say that he has skipped procedures in reaching his own conclusion.[8]
  4. And the conclusive test is that an expert is conservative and is cautious. It is well settled principle that the opinion of an expert should be taken with great caution, and moreover, the decision should not be based simply on the basis of opinion an expert, without a substantial corroboration as it is unsafe otherwise. The opinion of an expert by its very nature, weak, and infirm and in itself cannot of itself from the basis for a conviction and should be taken with great caution.[9]

Law Relating to Expert Witness

Law related to expert evidence is mentioned particularly in S.45 to S.51 of Indian Evidence Act and restricted to the interpretation of these sections only. However, in the course of time, the law related to expert evidence has been developed with the rapid development of technology and with the help of judicial decisions.

45. Opinions of experts

When the Court has to form and opinion upon a point of

  • foreign law
  • science or art
  • identity of handwriting 
  • finger impressions

 The opinions upon that point of persons specially skilled in the above mentioned fields.Such persons are called experts.[10]

If an expert is giving an opinion, it is considered as a relevant fact for the case. An expert has devoted his time in learning a special branch of expertise and thus is especially skilled in the subject. It can include:

  • Superior knowledge, and
  • Practical experience

The court of law, before admitting any of the opinion made by an expert, needs to ensure that the person is an expert under the law. If it is found that the person is not an expert, his opinion is discarded by the court. For checking that the witness is an expert, he must be examined and cross-examined [11].

In the case of Ramesh Chandra Agrawal vs Regency Hospital Ltd. & Ors.,  the court stated that the first and foremost requirement for expert evidence to be admissible is that it is necessary to hear the expert evidence. The test is that the matter is outside the knowledge and experience of the layman.[12]

Opinion for foreign law

When there is a law of prevailing in any foreign country which needs to be considered for giving judgement in any case, the court needs an expert who is well versed with that law.

Otherwise, the court can take opinion from a law-book which contains the answer regarding any foreign law. These books must be printed or published under the authority of the government of that country. Other reports of the ruling of the courts can also be taken as relevant which are given in such books of foreign law.

Opinion for fingerprint

Generally, finger impression expert’s opinion is given more value because: [13]

  • The fingerprints of any person remain the same from their birth till death, and
  • No two individuals are ever found to have the same finger impressions

Opinion for Science or Art

The words ‘Science and Art’ are to be broadly constructed. The term ‘science’ is not limited to higher sciences and the term ‘art’ is not limited to fine arts, but having its original senses of handicraft, trade, profession and skill in work.

To construe that if any expertise comes under the head of ‘art’ or ‘science’; the following tests can be applied :

  • Is the subject matter of the injury such that inexperienced people are not capable of forming a correct judgement without the assistance of experts?
  • Is the character of a science or art as such that it requires a course or a study to obtain a competent knowledge or skill.[14]

The scientific question involved is assumed to be not within the court’s knowledge. Thus cases, where the science involved, is highly specialized and perhaps even esoteric, the central role of an expert cannot be disputed.[15]

45A. Opinion of Examiner of Electronic Evidence.— When in a proceeding, the court has to form an opinion on any matter relating to any information transmitted or stored in any computer resource or any other electronic or digital form, the opinion of the Examiner of Electronic Evidence referred to in section 79A of the Information Technology Act, 2000 (21 of 2000), is a relevant fact.[16]

47. Opinion as to handwriting, when relevant

When the Court has to form an opinion as to the person by whom any document was written or signed, the opinion of any person acquainted with the handwriting of the person by whom it is supposed to be written or signed that it was or was not written or signed by that person, is a relevant fact.[17]

The handwriting of a person may be proved in the following ways:

  • A person who is an expert in this field
  • A person who has actually seen someone writing, or
  • A person who has received any document which is written by the person whose handwriting is in question or under the authority of such person and is addressed to that person
  • A person who regularly receives letters or papers which are written by that person
  • A person who is acquainted with the signatures or writing of that person[18]

State of Maharashtra v. Sukhdeo Singh, the Apex Court opined that before a Court can act on the opinion evidence of a handwriting expert two things must be proved beyond any manner of doubt, namely, (i) the genuineness of the specimen/admitted handwriting of the concerned accused and (ii) the handwriting expert is a competent, reliable and dependable witness whose evidence inspires confidence.[19]

47A. Opinion as to digital signature where relevant

When the Court has to form an opinion as to the digital signature or any person, the opinion of the Certifying Authority which has issued the Digital Signature Certificate is a relevant fact.

48. Opinion as to existence of right or custom, when relevant

When the Court has to form an opinion as to the existence of any general custom or right, the opinions, as to the existence of such custom or right, or persons who would be likely to know of its existence if it existed, are relevant.

49. Opinion as to usage, tenets, etc., when relevant

When the Court has to form an opinion as to the usages and tenets of any body of men or family, the constitution and government of any religious or charitable foundation, or the meaning of words or terms used in particular districts or by particular or by particular classes of people, the opinions of persons having special means of knowledge thereon, we relevant facts.

50. Opinion on relationship, when relevant

When the Court has to form an opinion as to the relationship of one person to another, the opinion expressed by conduct, as to the existence of such relationship, of any person who, as a member of the family or otherwise, has special means of knowledge on the subject, is a relevant fact.[20]

Cr.P.C. provides a list of some Govt. Scientific Experts as following: –

  • Any Chemical Examiner / Asstt. Chemical examiner to the Govt.
  • The Chief Controller of explosives
  • The Director of the Fingerprint Bureau
  • The Director of Haffkein Institute, Bombay
  • The Director, Dy. Director or Asstt. Director of the Central and State Forensic Science Laboratory.
  • The Serologist to the Govt.
  • Any other Govt. Scientific Experts specified by notification of the Central Govt.[21]

 Evidentiary Value of an Expert Opinion

The data given by the expert are relevant and admissible. If any oral evidence contradicts the data/ report; it will not make the data evidence obsolete. But, as per section 46, in case any fact is in contradiction to the opinion of the expert, that fact becomes relevant. If the opinion of the expert is relevant, the contradictory fact becomes relevant even though it was not relevant as such. The value of expert opinion depends upon the facts on which he is based and the competency of such expert in forming a reliable opinion.

If a judge relies upon the opinion of the expert only and not on the facts and the testimony of ordinary witnesses to give judgement then is the weakness of the case. This is because even if a person is an expert in his field, he cannot be termed as a direct witness and cannot give a statement on the facts of the case. He is just giving an opinion as per the evidences given to him and cannot draw a conclusion regarding the guilt of the accused in all the cases.[22]

The evidence given by the expert is just an opinion and is not a fact-based testimony and thus are given slight value. This is the reason that eye-witnesses or other factual witnesses are given a priority over the expert’s opinion. This is because opinion evidence cannot supersede substantive evidence. No expert can claim that he could be absolutely sure that his opinion was correct, expert depends to a great extent upon the materials put before him and the nature of the question put to him. [23]

A Court is not bound by the evidence of the experts which is to a large extent advisory in nature. The Court must derive its own conclusion upon considering the opinion of the experts which may be adduced by both sides, cautiously, and upon taking into consideration the authorities on the point on which he deposes.[24]

The value of expert opinion rest on the facts on which it is based and his competency for forming a reliable opinion. The evidentiary value of the opinion of expert depends on the facts upon which it is based and also the validity of the process by which the conclusion is reached. Where the experts give no real data in support of their opinion, the evidence even though admissible, may be excluded from consideration as affording no assistance in arriving at the correct value.[25]


From the above study is clear that the expert witness opinion on binding upon the judges it just acts as an assistance to the judges and helps them to draw a conclusive line in a particular case. hence the opinion of the expert witness is not substantive piece of evidence as well it is nor a conclusive evidence. Without corroboration of the opinion from other evidence it may not have any value in the eyes of law.


[2] Carl Meyer (1999), ‘Expert witnessing – explaining and understanding Science’,1st Ed., CRC Press.

[3] Parat versus Bissessar, ILR 39 Cal 245.

[4] Raj Kishore versus State, AIR 1969 Cal 321.

[5] Balkrishna Das Agrawal versus Radha Devi, AIR 1989 All 133.


[7] Dhobi Yadav versus State of Bihar, AIR 1989 (2), Cr. L.C., 629 at para 641.

[8] C.K. Johari, IDENTIFICATION OF FINGERPRINTS AND LAW, 2 J.T.R.I. Journal, 1-5 (1995).

[9] Magan Bihari Lal versus State of Punjab.

[10] Section 45 of Indian Evidence Act 1872.

[11] Balkrishna Das Agarwal versus Radha Devi, AIR 1989 All 133.

[12] Ramesh Chandra Agrawal versus Regency Hospital Ltd & Ors, 2009 INSC 1569.

[13] Sadhana.S, K. Roja, A Study on the Admissibility of expert evidence in Indian.

[14] Noshirvan H. Jhabvala. The Indian Evidence Act (Act 1 Of 1872). 106 (2013).

[15] Law relating to Expert Opinion under the Indian Evidence Act. VAKILNO.1.COM (2018)

[16] Section 45(a) of Indian Evidence Act 1872.

[17] Section 47 of Indian Evidence Act 1872.


[19] State of Maharashtra Versus Sukhdeo Singh 1992 AIR 2100.

[20] Indian Evidence Act 1872.

[21] Section 293 of Criminal Procedural Code 1973.


[23] The State (Delhi Administration) v. Pali Ram, AIR 1979 SC 14.

[24] Malay Kumar Ganguly v. Sukumar Mukherjee.

[25] Extract from the Article “Relevancy of Expert’s Opinion”

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