Whenever an application is made pursuant to law for a permit to cremate the body of any person, the department, board or office in which such application is filed shall forward such application to the chief medical examiner who shall thereupon cause an investigation and report to be made thereon. In the event that the chief medical examiner, or a deputy chief medical examiner, or a medical examiner shall, in the course of such investigation, determine that reasonable grounds exist therefor, an autopsy shall be performed upon such body by a medical examiner. Where indicated, the autopsy shall include toxicologic, histologic, microbiologic and serologic examinations. A detailed description of the findings of all autopsies shall be written or dictated. The findings of the investigation, the autopsy and any toxicologic, histologic, serologic and microbiologic examinations, and the conclusions drawn therefrom shall be filed in the office of chief medical examiner. Such findings and conclusions shall be signed by the medical examiners performing the autopsy.