Rogge told a press conference in Athens today: “We hope Dwain Chambers will be sensible enough to come forward to give information and in return he will get a reduction of his penalty.”

When an athlete is deemed to have been particularly useful to investigators, rules do allow for it to be reflected in a lesser penalty.

Currently athletes found guilty of using banned substances face a minimum two-year ban as well as being permanently excluded from the Olympic Games.

Chambers faces a suspension after both his A and B samples proved to be positive for THG at an out-of-competition test in Saarbrucken on August 1.

The 25-year-old has consistently protested his innocence and denies taking banned substances.

Meanwhile, it has been reported that Chambers is one of the two athletes who tested positive at the World Championships.

IAAF media director Nick Davies said: “At this point I cannot confirm it is Dwain Chambers. Any announcement must come from UK Athletics.”

A spokeswoman for UK Athletics said: “We cannot confirm the results of any drugs tests under our confidentiality rules.

“We can only comment after the B test or if the athlete himself reveals he has tested positive.”

Chambers’ lawyer Graham Shear also refused to comment.