Sailor on nuclear Vanguard-class submarine is investigated over 'stealing secrets' after confidential papers are found on his Huawei phone

A Royal Navy sailor is under investigation on suspicion of stealing secrets from a nuclear submarine.

Military police at the nuclear sub base HMNB Clyde, at Faslane, Scotland, allegedly found confidential papers on Marcus Gauntlett's Huawei mobile phone.

The 36-year-old is being held on suspicion of breaking the Official Secrets Act.

The Able Seaman was serving as a steward on a nuclear-armed Vanguard-class submarine, reported The Sun. 

The submarine acts as the UK's nuclear deterrent and is armed with Trident 2 D5 missiles. 

Sources say the phone was seized as part of a separate investigation with investigators ruling out espionage. 

The source said the papers allegedly showed classified submarine movements. 

A Ministry of Defence spokesperson said: 'We can confirm that a member of the Armed Forces is under investigation.'

In March, a group of Royal Navy sailors were arrested on suspicion of stealing laptops and iPads from a duty free shop on an American base in Bahrain.

The sailors were suspected of using security alarm proof bags to snag the items from the Main Navy Exchange store, The Sun reported. 

The group of around seven servicemen then allegedly sold the stolen goods to others at half the retail price.

Some of the sailors were arrested by 'American armed military police' in January, a source has claimed. 

Others were reportedly marched off of the HMS Middleton in handcuffs following a joint investigation by the UK and US.

A Royal Navy spokesperson told MailOnline at the time it is aware of the alleged incident, which is currently 'under investigation'.