President John F Kennedy had a special room in the White House just for his gay best friend, a book claims.

The little-known factoid came to light in ‘Jack and Lem: The Untold Story of an Extraordinary Friendship’ – first published in 2007.

The book deals with the late President’s lifelong friendship with Kirk LeMoyne ‘Lem’ Billings, after the pair first met in prep school.

The pair were inseparable, with Mr Billings helping run Kennedy’s Presidential campaign and serving as an usher at his wedding.

According to author David Pitts, the pair were so close that they wrote lengthy letters whenever they were apart – and Billings even had his own room at the White House.

Though Mr Billings never came out as gay, newspaper editor Ben Bradlee – a mutual friend of the pair – admitted: “I suppose it’s known that Lem was gay….It impressed me that Jack had gay friends. Everybody knew, but that’s not the kind of thing you talked about in those days.”

Documents from the John F. Kennedy Library and the Massachusetts Historical Society shed light on the pair’s close friendship – with Jackie Kennedy even remarking on the amount of time the pair spent together.

The pair’s friendship came despite the staunchly Catholic background of the Kennedy family

In a 2009 interview, Pitts told Woolf and Wilde: “The way I would characterize it is that is was a very close, deep, friendship across sexual orientation lines.

“This was the closest person in all the world to him outside of his family for 30 years. He wasn’t just ‘a gay friend’ on the side.”

He continued: “Some of the people who were working in the White House very close to JFK didn’t know it. For example, Ted Sorensen whom I interviewed for the book, perhaps the closest aide to JFK, saw Lem around the White House all the time… but he told me he didn’t know that he’d had his own room there and was staying there so much of the time.

“That’s another indication of the depth of the attachment.”

Though Pitts does not cast aspersions on the nature of the pair’s relationship, author Jerry Oppenheimer did in subsequent book RFK Jr. and the Dark Side of the Dream – in which he claims the pair had “a friendship that included oral sex, with Jack always on the receiving end”.

Mr Billings died in 1981, 18 years after Kennedy was assassinated in office.