Hungarian weightlifter Ferenc Gyurkovics has been stripped of his silver medal and thrown out of the Olympic Games after testing positive for a banned steroid.

Puerto Rican wrestler Mabel Fonseca, who did not medal but took fifth place in her event, has also been thrown out for a steroids offence.

Gyurkovics competed on Tuesday in the 105kg weightlifting event, but the 24-year-old's post-event test showed up Oxanfrolone, a banned steroid, and the medal positions will change as a consequence of his disqualification.

Moving up to take silver will be Ukrainian Igor Razoronov, while Russian Gleb Pisarevskiy steps into the bronze position after being originally classified fourth.

Fonseca, who is 32 and a PE teacher from San Juan, tested positive for stanozolol.

She was competing in the 55kg wrestling on August 23.

Stanozolol was among the drugs to which the World Anti-Doping Agency chief Dick Pound referred to this week when describing users of such drugs as suffering from "complete arrogance or stupidity", because of the ease in which they are detectable.

It was also the drug which Ben Johnson tested positive for at the Seoul Olympics in 1988.

Earlier it was revealed that hammer gold medallist Adrian Annus will return to Athens to testify before an IOC disciplinary hearing tomorrow.

Annus, who tested negative at a drugs test after his final, failed to show up for a second test on his way home to Hungary.

The International Olympic Committee stressed at their Athens press briefings yesterday and today that they are keen to trace Annus' whereabouts.

But Hungary Olympic chief Pal Schmitt insisted that Annus was voluntarily planning to return to Athens tomorrow.

Schmitt said: "He wants to come to explain.

"He was not in the physical condition to take the test that he missed."

Annus announced his retirement upon returning to Hungary.