A Royal Navy sailor sexually assaulted a colleague using a beer bottle in a drunken prank on board a warship while it was docked in Bournemouth, a court martial has heard.

The alleged incident happened aboard the Plymouth-based frigate HMS Northumberland as it was alongside the Bournemouth coast for the air show in August 2013.

The court was told the alleged assault was filmed on a mobile phone and shown to other members of the ship's company.

Nadim Bashir, prosecuting, told the trial at Portsmouth Naval Base's court martial centre that the alleged victim had been drinking heavily after being invited to an event at the petty officer's mess.

Having thrown up several times, he had fallen asleep on a seating area and someone had placed a duvet over him when the alleged attack took place.

Logistician Andrew Donaldson, 34, denies a charge of assault by penetration using a beer bottle and an alternative count of disgraceful conduct of an indecent kind.

Leading Seaman Christopher Cook, 31, denies a charge of disgraceful conduct of an indecent kind.

Mr Bashir said: "Matters were to escalate rapidly. Donaldson took hold of a beer bottle and made a statement for those viewing the video of his intentions.”

Mr Bashir said that the alleged incident had been filmed by Leading Logistician Roger Spratt on Donaldson's mobile phone and photographs were also taken "for the amusement of others".

In a statement read to the court, the alleged victim said that he had drunk six cans of Bulmer's cider in an hour which had caused him to vomit several times.

He said: "I was very drunk, for this to wake me up demonstrates the force used. At no time have I given anyone permission to touch me or carry out such an act."

The panel of senior officers judging the case were shown the video footage of the alleged assault.

The trial was told that Donaldson does not deny carrying out the action although he cannot remember but denies that it was of a sexual nature.

Cook provided no comment when interviewed by police.

The trial continues.