Justin Welby
The Archbishop of Canterbury lived with his father from aged three Reuters

The next Archbishop of Canterbury, Justin Welby, has discovered details of his late father's secret life, including his real name, his German-Jewish heritage and an affair with a sister of JFK, Patricia.

In his first interview since being appointed leader of the Anglican Church, Welby discussed his relationship with his father Gavin, who struggled with alcoholism throughout his life.

But the Daily Telegraph shocked Welby by revealing details of his father's life of which Welby was munaware.

The paper claimed that Welby's father's real name was Bernard Gavin Weiler, the son of a Jewish immigrant from Germany, who earned money in the US bootlegging whiskey alongside the Italian mafia during the prohibition.

His father also married in the US, which he kept secret his entire life along with his Jewish heritage, had an affair with the sister of John F Kennedy and later dated the actress Vanessa Redgrave.

When he returned to Britain, he stood for parliament as a Conservative candidate but was sued for libel by his Labour opponent, Richard Crossman.

Welby, Bishop of Durham, discussed how as a teenager at Eton he nursed his father through his dependency.

"It wasn't an easy upbringing. Living with someone who's got an alcohol dependency is complicated - to put it at its mildest," he said.

"He was very affectionate, brilliant intellectually but quite demanding."

He said of the revelations of his father's secret past: "It is quite a remarkable story. I would have thought 'wow, that's a fantastic story' if he had told me about it as a child."

Welby was 21 and studying at Trinity College, Cambridge, when his father died of a heart attack in 1977. The Telegraph said that both the name and date of birth given at his father's death were incorrect.

Welby was brought up by his father from the age of three, but admits he knew little of his background until recently.

"I lived with him but I didn't know him very well. He told lots of stories but one was never really sure what was true and what wasn't. He drank quite heavily and he would say things sometimes when he had been drinking and you did not know what was true or not."