Justin Timberlake once broke into Alcatraz prison

Justin Timberlake once "accidentally broke into" Alcatraz prison.

The 39-year-old singer has revealed that in 2000 he was filming a music video with boy band NSYNC near Alcatraz Island, when he and his bandmate Joey Fatone snuck into a guided tour of the maximum security prison, which closed as a jail in 1963 and once housed infamous crime boss Al Capone.

Explaining the story during an appearance on 'The Ellen Degeneres Show', Justin said: "I accidentally broke into Alcatraz one time. I was in a group called NSYNC ... We were shooting a video in the redwoods outside of San Francisco and we ended up shooting this one scene on this pier directly opposite Alcatraz.

"And at the time I was watching 'The Untouchables' over and over again, and I was obsessed with the fact that Al Capone, you know, they put him in Alcatraz.

"And I said: 'Who wants to go see Alcatraz with me?' and Joey - who's usually game for anything - he was like: 'I'll go with you!' but we only had basically an hour in between where they were setting up a different shot.

"So the fire department was waiting around and they came up and said: 'Hey could we take some pictures with you guys?' and Joey and I were like: 'Sure ... would you take us to Alcatraz?'

"They were like: 'Yeah, sure!' so they take us over - we felt so cool - on like a coast guard, fire department boat."

Justin and Joey were then taken to the island, not realising that those who visit the island via tourist ferry have their tickets checked when they arrive on the island.

And without tickets, they decided to sneak into the prison instead of joining the tour.

The 'Man of the Woods' singer continued: "We get over there and we realise that on the mainland you're supposed to buy your tickets and then get on the ferry!

"So, we get to the main gate and they're like: 'Tickets please' and so of course we were like - I mean I was just outta high school - so I was used to this one ... I was like: 'Yeah the guy behind me has the tickets' and we ended up sort of sneaking in and getting the earphones and weaving our way into one of the tour groups."

The pair eventually got caught - just as Justin had arrived at Al Capone's cell.

He said: "And by the time we got half way through and just gotten to Al Capone's cell, I got a tap on my shoulder. And they're like: 'Come with me' and I was like: 'Joe, we are gonna go down in history as the dumbest people ever. We got caught breaking into a prison!'

"They let us go away with a warning, and obviously we had to pay for the tickets."