When autopsies and extra death investigations can happen

[(a)] If, in the opinion of the coroner, or of the coroner's physician, or of the prosecuting attorney, or of the chief of police (in the city and county of Honolulu), an autopsy of the remains of any human body appearing to have come to death under any of the circumstances set forth in section 841-3 is necessary in the interest of the public safety or welfare, that person shall cause to have performed, such an autopsy. If, in the opinion of the coroner's physician, a further or additional investigation as to the cause of death is necessary, the coroner's physician may conduct the same or have the same made, and the expenses thereof shall be paid by the county concerned, and for this purpose, the coroner's physician shall have the duties and powers conferred upon the coroner or deputy coroner by sections 841-4 to 841-8. [(b)] Any law to the contrary notwithstanding, the coroner's physician or medical examiner of any county (including the city and county of Honolulu) may cause to have performed an autopsy to determine cause of death upon the remains of any human body which is brought into or found within the State and which appears to have come to death under any of the circumstances set forth in section 841-3, even though such circumstances may have occurred without the State. The coroner's physician or medical examiner of any county (including the city and county of Honolulu) shall have the right to retain tissues, including fetal material, of the body removed at the time of autopsy to be used for necessary or advisable scientific investigation, including research, teaching, and therapeutic purposes.