Former Olympic champion Linford Christie has been cleared by UK Athletics, the governing body of British athletics, of doping after testing positive for the banned steroid nandrolone earlier this year. However, IAAF, the world athletics governing body, has said that might not be the end of the matter.

IAAF general secretary Istvan Gyulai said: "It is possible it is not the end of the matter. The problem is UK Athletics say it is not proven beyond reasonable doubt (that the steroid was derived from a prohibited substance). The IAAF rules (that) if it is in your body it doesn't matter where it came from. It is up to the athlete to prove it came from natural sources.

"I am sure UK Athletics made a decision based on some evidence and we are very much looking forward to seeing what that evidence was."

In clearing Christie, UK Athletics said in a statement that it could not be proved beyond reasonable doubt that the steroid "was derived from a prohibited substance" and therefore the athlete had been cleared on all charges.

Jayne Pearce, spokeswoman for Britain's governing body, said: "As far as UK Athletics are concerned the matter is concluded and at an end. It's really up to the IAAF whether they want to re-open the case and take it to arbitration."

Christie (39) has been in semi-retirement since 1997 but raced as a one-off in an indoor meeting in Dortmund, Germany, on February 13th. He has always denied taking the performance-enhancing drug.

UK Athletics also cleared Britain's European 200 metres champion Doug Walker in July after he tested positive for the same drug. That decision was rejected by the IAAF which is conducting further investigations.

Christie, currently filming a new television series, was delighted to hear the result of the hearing.

"I was always confident of this outcome having maintained from the outset that I had done nothing wrong," he said. "I'm looking forward to getting on with my life."