Section 13

Any person who is not mentally disordered and who is 18 years of age or above may either in writing at any time or orally in the presence of 2 or more witnesses during his or her last illness authorise the post‑mortem examination of his or her body for the purpose of establishing or confirming the cause of death or of investigating the existence or nature of abnormal conditions.

Such authority is effective upon the death of that person.