Reports of investigations and autopsies, and the records thereof, on file in the Office of the Chief Medical Examiner or in the office of any county medical examiner, shall be received as evidence in any court or other proceeding, and copies of records, photographs, laboratory findings and records on file in the Office of the Chief Medical Examiner or in the office of any county medical examiner, when attested by the chief medical examiner or by the county medical examiner, assistant county medical examiner or coroner in whose office the same are filed, shall be received as evidence in any court or other proceeding for any purpose for which the original could be received without any proof of the official character of the person whose name is signed thereto unless objected to by counsel: Provided, That statements of witnesses or other persons and conclusions upon extraneous matters are not hereby made admissible.