Section 307(a) in Police Regulations, Bengal , 1943
(a)The police officer sent in charge of a corpse need not be present throughout the details of the post-mortem examination. It will suffice if he stands sufficiently near to be able to testify that the body which had been in his charge was the one examined by the medical officer. He should be present at the Court when the medical officer's testimony as to the result of the examination is given, in order that the identity of the body examined, with the body to which the criminal case relates, may be established, if necessary.