Former world heavyweight boxing champion Muhammad Ali has Irish roots, according to researchers.

Ali is thought to have descended from an Irishman who emigrated to the United States in the 1860s.

Genealogists have unearthed evidence that an Abe Grady settled in Kentucky and later married an African-American woman.

Ali was ultimately descended from that union.

"We would like to honor Ali as one of the heroes of the 20th century and invite him here," said Michael Corley, a local council leader in the small town of Ennis in the south west of Ireland.

Antoinette O'Brien, of the County Clare Heritage Centre, confirmed the findings.

"Through research being carried out for the Irish-language TV station TG4 on Ali, we established that Ali's great-great grandfather, John Grady, the father of Abe, rented a house and a small garden in Ennis in 1855," she said.

"There is no doubt that Abe Grady was Ali's great-grandfather."

But Ali's publicist Jill Siegel, speaking from New Jersey, said the legendary fighter already knew of his Irish ancestry.