Normally witnesses are not entitled to give their opinion in any proceedings. They should tell whatever they see or observe but Section 23 of Evidence Act 2031 provides for admission of opinions of different types of Experts in court, and the value to be given on such opinions as follows;
- If court has to form an opinion of foreign law, science, art, handwriting or finer impressions, it may take the opinions of experts of such subject as evidence.
- If court has form an opinion on handwriting of a person, it may take opinion of a person who has had opportunity to see handwriting and is in a situation to identify handwriting as evidence.
- If court has to form an opinion as to relationship between persons, it may take as evidence the opinions of people who have special knowledge of relationship.
- If court has to form an opinion as to meaning of certain words placed in certain places , it may take the opinion of person having special knowledge of same as evidence.
- Such opinions are however to be admitted as evidence only if an expert comes and testifies in the court.The expert’s opinion is only piece of evidence and cannot be taken as substantive piece of evidence since it is to be judged along with other evidence. In other words, expert’s opinion must be corroborating with the other evidence. As for instance, report of handwriting expert is not admissible in evidence in the absence of formal proof. In the case of Mubark Ali vs.State of Bombay, the Indian Supreme Court laid down that a witness must confine himself to the facts and not to state of his opinion. But according to Section 23(7) of Evidence Act 2031, author of an article or book need not be present in the court in person for the article or book to be admitted as evidence. And also , if the Post Mortem Report does not contradict with other facts collected during the course of investigation or if the opponent does not challenge matter in court, the Expert need not come to the court.