Australia has appealed to sport's highest international arbitration body to disqualify American cyclist Tyler Hamilton from the Olympics, clearing the way for Australian Michael Rogers to collect a bronze medal.

The Australian Olympic Committee (AOC) has joined Russia to argue in the Court of Arbitration of Sport (CAS) that Hamilton should be disqualified from the Olympic time trial.

Gold medallist Hamilton was suspended by his Phonak team a day after he won a time trial on the Tour of Spain after results from two failed blood tests suggested he had been guilty of an illicit blood transfusion.

Hamilton's A sample taken in Athens a month earlier had produced similar results although the International Olympic Committee (IOC) could not test his B sample, which is needed to sanction any athlete, because it had been frozen instead of being refrigerated, rendering it untestable.

The cyclist, who was allowed to keep his gold medal, has denied ever having used a blood transfusion but still faces a two-year ban following a failed doping test in the Tour of Spain.

AOC director of sport Craig Philips said Australia hoped to boost its medal haul from Athens if Hamilton was stripped of his medal and Rogers, who finished fourth in the time trial, received bronze while silver medallist Viatcheslav Ekimov from Russia would be crowned the new Olympic champion.

"Given there was blood doping, we think there is a chance that even though there has been some contamination of the B sample there may be an argument to say, well, the B sample may not be relevant," he said.

"That's the case we're now pursuing with the Court of Arbitration for Sport along with the Russians.

"We're hopeful that something might happen and it will be good for Michael if it does."

AOC media director Mike Tancred said AOC lawyer Simon Rofe was heading the appeal, which had received backing from Cycling Australia and Rogers.

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