The four-times American Olympic gold medal sprinter, who is now retired, predicts black Olympians will dominate at London 2012, putting their prowess down to a “superior athletic gene” found in the descendants of West African slaves, reports the Daily Mail.

He said he welcomes an open discussion of the controversial topic, which is taboo in the United States.

“All my life I believed I became an athlete through my own determination, but it’s impossible to think that being descended from slaves hasn’t left an imprint through the generations,” he told the newspaper.

“Difficult as it was to hear, slavery has benefited descendants like me – I believe there is a superior athletic gene in us.”

Ussain Bolt, who is the current 100m world champion and tipped to claim gold again at this year’s Olympic Games, is from the plantation town of Trelawny Parish in Jamaica. The plantation was owned by British Olympic boss Lord Sebastian Coe’s ancestor George Hyde Park, who had 297 slaves.

At the Beijing Olympics, eight 100m finalists were black and believed to be the descendants of slaves.

Texas-born Johnson, 44, who is a BBC commentator underwent DNA testing as part of a new documentary Michael Johnson: Survival Of The Fastest.