Doctors who perform unnecessary physical examinations on patients could be engaging in sexual assault and risk facing criminal charges under tougher rules announced by the Medical Board of Australia.

In its revised Sexual Boundaries in the Doctor-Patient Relationship guidelines, which take effect on December 12, the health regulator has, for the first time, given explicit parameters for physical examinations and social media use.

The Medical Board of Australia has released guidelines on sexual boundaries.

It said "unwarranted physical examinations" or "inappropriate touching" may constitute sexual assault and health authorities would ensure reports of "criminal behaviour" reached the police.

"This includes conducting or allowing others, such as students, to conduct examinations on anaesthetised patients, when the patient has not given explicit consent for the examination," it reads.