SYDNEY, Australia — The first group of athletes to disappear from the Gold Coast Commonwealth Games were weight lifters and boxers from Cameroon.

More athletes from more countries followed, and while much of Australia wondered what was going on, Lamin Tucker knew — because 12 years ago, he had been one of them. After finishing his last race in the Melbourne Commonwealth Games, he walked into the city’s streets with nothing but a phone in his pocket.

“They are refugees in danger,” said Mr. Tucker, a former sprinter from Sierra Leone who is now an Australian citizen, referring to the largely African cohort of athletes who went missing after April’s Games in the City of Gold Coast. “These people who came here, who run away, they run away because they want freedom.”

The number of athletes and officials from the recent games who stayed in Australia has now ballooned to roughly 250. For the most part the athletes have gone underground, keeping low profiles to evade attention from the authorities in Australia and their home countries.