Muhammed Ali's world title fight against Sonny Liston in 1964 was one of the most anticipated and watched boxing bouts in history.
It is arguably the fight that made the then Cassius Clay when he beat the seemingly invincible Liston in the seventh round after the reigning champion refused to leave his corner.
Now 50 years on, classified files reveal the FBI bosses suspected it wasn't a fair fight, and that the Mafia may have been involved.
Within weeks of the fight, Clay changed his name to Muhammed Ali, became a figurehead for the civil rights movement and would eventually refuse to fight in Vietnam.
The files reveal the FBI believed Mafia bosses in Las Vegas made millions of dollars, as did Liston betting on the champion to loose.
The information held by the FBI was so secret, only a few agents had access to it, including the director at the time J Edgar Hoover.
Daily Mail sports columnist Jeff Powell told ITV News the allegations were never proven and were based "principally on the fact that people couldn't believe that Liston lost to this brash, young kid called Cassius Clay."