A whistleblower who went on the run after publishing a dossier on 30 alleged safety and security concerns about Britain’s nuclear deterrent has handed himself in to police upon his return to Britain.

William McNeilly, 25, is now being held at a secure military base in Scotland, according to authorities.

The young submariner released an 18-page report online this month, which claimed the Vanguard-class submarines that carry Britain's Trident missiles were “a disaster waiting to happen.”

He is believed to have been apprehended by UK authorities at Edinburgh airport on Monday evening.

A Royal Navy spokeswoman told RT McNeilly was stopped on Monday night at Edinburgh airport, and is now being detained by Royal Navy police at a military base in Scotland.

She said the young submariner is being “afforded the duty of care” the Royal Navy offers to all of its staff.

READ MORE: ‘Nuclear disaster waiting to happen’: Royal Navy probes Trident whistleblower's claims

The Royal Navy spokeswoman insisted the force rejects McNeilly’s “subjective and unsubstantiated personal views” but that it takes the operations of its submarines and the safety of its staff “extremely seriously.”

She said the body would continue to investigate the issue comprehensively.

The whistleblower’s brother, Aaron McNeilly, said on Facebook on Tuesday morning he felt “happy” his sibling was “safe and well.” He later added his brother was in Scotland, after handing himself in.

In a lengthy Facebook statement on Monday afternoon, McNeilly announced that he was ready to turn himself him after days on the run.

Addressing followers on Facebook, he said:

“I'd rather this was an informative resource for those interested in the case, I am not involved at all with him I just want to get his message out.”

“Anyone that thinks its better to invest £100bn in times like these on nuclear weapons over than over the future of children in this country is pure madness in this age,” he added.

“It's a sad sight when what looks like military personal, their friends and family have come on here to vent but are behaving like kids.”

A few hours before, he revealed his identity by posting a picture accompanied by the caption: “Some of you may already know I’m an engineering technician on the UKs nuclear weapon system (was), but what you don’t know is, I’ve been working covertly to eliminate the biggest threat to the UK for about a year.”

He also claimed in the statement to have moved between countries and locations on a daily basis using multiple aliases.