A watchman was caught drinking beer and falling asleep on a nuclear submarine which crashed in the Red Sea last week, Sky News reported Tuesday.
The crewman has been placed on leave from the HMS Superb while a Ministry of Defense investigation is carried out.
His conduct came to light after cellphone footage obtained by The Sun newspaper showed a commander warning crew about safety breaches that he said were "unacceptable" and irresponsible.
The officer is identified by the paper as Executive Officer Lieutenant Commander John Aitken.
He says on the video clip: "You know far better than to allow stuff like that to happen. As submariners, you accept responsibility for yourselves and your shipmates."
The HMS Superb crashed into rocks in the Red Sea on May 26, damaging its sonar equipment and forcing it to surface.