The man, believed to be an African middle distance runner in his 20s, was being held by the UK Borders Agency last night after walking into a police station in Leeds.

The athlete claimed he was being persecuted in his homeland.

It follows warnings from immigration officials that they fear up to 2 percent of athletes, team officials and supporters may claim refuge in the UK during and after the Games or try to stay on once their visas expire.

A spokesman said: “He was handed over to the UK Border Agency, who are now dealing with it.”

Home Office sources said the man was in secure accommodation outside London while officials looked into his case.

His attempt to claim asylum will almost certainly rule out his participation in the Games.

While they expected asylum claims, what has surprised officials is that the application was made before the athlete had competed. Most claims at previous Olympics and Commonwealth Games have been made post competition.

Investigators have identified several countries where they ‘expect’ asylum claims from athletes and supporters given visas specifically to attend London 2012, several are African and Middle Eastern.

Asylum claims are not unusual at Olympics and other sporting events.

At the 2002 Commonwealth more than 20 members of one West African country went ‘missing’ from their team camp and sought to stay-on in the UK while at one major games in Australia 22 competitors from five different African nations sought sanctuary.