The United States has a long tradition of presidential hopefuls drawing on their Irish connections to win votes.

Hillary Clinton has already been working her Irish links, through her husband, Bill, but now she finds competition from the least likely source.

Family historians have unearthed the Irish roots of Barack Obama, the son of a Kenyan goatherder who is being touted as potentially the first black US president.

Ancestry.co.uk identified his great-great-great-grandfather on his mother’s side as Falmouth Kearney, who fled Ireland and the Great Famine at the age of 19. He arrived in New York from Liverpool on March 20, 1850, then moved on to Ohio to be among relatives.

Simon Harper, managing director of the website, said: “A great deal has been made of Obama’s Kenyan roots, however, his European ancestry has been overlooked.

“If Obama becomes the next US president, he may well be the first to have Kenyan ancestry, but he will also join a long list of those with Irish ancestry, including Bill Clinton, Ronald Reagan, and of course, John F. Kennedy.”

The first mention of Mr Obama’s Irish ancestor was found in the 1860 US Federal Census, which listed his occupation as a farm hand.

Times Recommends

• Michael Jackson: Not the final chapter
• Indian Army spends10m rupees on golf buggies
• Sacha Baron Cohen forced to tone down Brüno