A Canadian businessman, claiming to be the secret love child of former American President John F Kennedy, has called on the family to provide a DNA sample for testing to prove it.

Jack Worthington (46) insists he is the illegitimate son of Kennedy born of a fling between his Texan mother and the American president in 1961, the Daily Mail reported.

Mr Worthington, who lives in British Columbia, Canada, says he wanted nothing from the Kennedy family except a DNA sample to prove his claim.

In a brief interview with a Canadian newspaper, Mr Worthington gave few details of his claim but did not explain why he had waited so long to come forward“It’s simply a profound duty I feel to do the right thing. Many Americans won’t agree and will want to sweep the dirt under the rug. Unfortunately, I’m a born whistleblower,'” he said.

He said his mother was introduced to Kennedy by vice-president Lyndon Johnson. Mr Worthington revealed his identity after reports surfaced in the US press that Vanity Fair magazine had been investigating his claims for 18 months. “Vanity Fair needs help. We need JFK DNA  and barring that, DNA from any male Kennedy directly related to Joe Kennedy [JFK's father],” he said.

The revelation, if proved true, could have an impact on the Democratic presidential race. The New York Post reported last week that Senator Ted Kennedy, JFK’s brother, had intervened to try to quash the story.