Chambers will still have to qualify in order to compete at the London Olympic Games.

Former drugs cheat Dwain Chambers will be free to compete at the London 2012 Olympic Games after the British Olympic Association lost a battle to enforce lifetime bans, according to reports.

The BOA's policy was overturned at the Court of Arbitration for Sport (Cas) after a protracted fight with the World Anti-Doping Agency (Wada), the BBC reported.

The decision means Chambers, 34, and cyclist David Millar, 35, who both served two-year bans for doping offences, are free to attempt to qualify for a place in Team GB.

It is expected that Cas will announce its formal decision on Monday.

Wada had said that the BOA's policy of lifetime Olympic bans after athletes served suspensions was not acceptable within its own codes.

The BOA wanted to keep the bans for taking performance enhancing drugs to dissuade other athletes from becoming tempted to cheat. It argued the drugs ban was part of its Olympic selection criteria, and not an extension of athletic bans.

But Cas said that the BOA's stance was unsupportable, and despite the support of the International Olympic Committee and many British athletes, the ban looks set to be overturned.

In a statement the BOA said: "The British Olympic Association can confirm that today, it has received from the Court of Arbitration for Sport the written decision in the arbitration between the BOA and the World Anti-Doping Association.

"As the decision is to be announced first by CAS, and out of respect for CAS and the Arbitration Panel, the BOA will be offering no comment today."