A nurse was allegedly assaulted and illegally arrested when she told a detective she could not take a blood sample from an unconscious patient.

Alex Wubbels told a police officer she could not take blood from the victim of a lorry crash because he could not consent, and the officer had produced no warrant.

Footage taken by University Hospital, in Salt Lake City, Utah, and Detective Jeff Payne's body camera show he threatened Ms Wubbels with jail if she did not comply, despite her having checked the policy with her bosses, the Salt Lake Tribune reported.

As Ms Wubbels, a former Winter Olympian, is dragged from the hospital to a police patrol car, she can be heard to scream: "Help! Help! Somebody help me! Stop! Stop! I did nothing wrong!"

In the end she was not charged but told the paper: "It hurts to relive it."

University Hospital's policy states blood cannot be drawn from an unconscious patient unless they have been arrested, a warrant for the procedure is granted, or the patient consents, the Tribune reported.

Detective Payne cited a now-outdated "implied consent" law to make his case, it said.

Ms Wubbels' lawyer told the paper she had not filed a lawsuit, but that following discussions with Salt Lake City police, she believed the department would now educate its officers.

Salt Lake City police told the Tribune they were investigating the incident, but that Detective Payne remained on duty.

It has provided training for other officers following Ms Wubbels' arrest.