49 CFR § 831.10 - Autopsies and postmortem testing.
When a person dies as a result of having been involved in a transportation accident within the jurisdiction of the NTSB -
(a) The NTSB is authorized to obtain, with or without reimbursement, a copy of a report of autopsy performed by a State or local authority on such person.
(b) The NTSB may order an autopsy or other postmortem tests of any person as may be related to its investigation of a transportation accident. The IIC may direct that an autopsy or other test be performed if necessary for an investigation. Provisions of local law protecting religious beliefs with respect to autopsies shall be observed to the extent they are consistent with the needs of the investigation.