Saeed Ahmed, 29, from the southern city of Basra, is seeking asylum in the United States. He said: "I have seen with my own eyes [Saddam's] cousin, Ali Majid, shoot innocent civilians."
Mr Ahmed did not say whether or not he was a Shia Muslim, a majority in the Basra area where Iraqi President Saddam Hussein, a Sunni Muslim, has violently put down several uprisings in recent years.
The athlete said he tricked Iraqi intelligence officers, accredited as team officials but acting as "minders", before a team trip to Atlanta's zoo on Wednesday. "I told them I had to go back to my room to change clothes. Then I made a run for it from the Olympic village," he said.
He said he had been helped by two members of a local anti-Saddam group, one of them reportedly a Briton, who had first approached him with a message offering to assist him.
One of them, Omar Muhamed, a student at a technical college in Atlanta, said he had posed as an Argentine athlete last week, approached Mr Ahmed in the Olympic village where the athletes are staying, and slipped him a letter in Arabic offering to help him defect.
Mr Ahmed later sprinted from the Olympic village to a nearby petrol station where Mr Muhamed and Francis Brooke, reportedly a Londoner now resident in the US, were waiting in a car. "He was running, sweating. He was very afraid and nervous," Mr Muhamed said later.
Making detours in case Iraqi intelligence officers followed them, the two men drove Mr Ahmed to a "safe house" outside Atlanta and introduced him to a lawyer.
Thomas Fischer, a spokesman for the local offices of the US Immigration and Naturalisation Service, said last night that the athlete had not yet formally applied for asylum.
An "associate" of Mr Ahmed had contacted the immigration service on his behalf and the athlete was likely to be interviewed this week, he said.
Mr Ahmed finished 23rd of 28 competitors in the 99kg class of the weightlifting event.Reuse content