Hungarian weightlifter Ferenc Gyurkovics has been thrown out of the Olympics after testing positive for the banned substance oxanfrolone.
Gyurkovics had set an Olympic record by lifting 195kg in the snatch on Tuesday to win the silver medal.
Puerto Rican wrestler Mabel Fonseca, who was fifth in the women's 55kg category, has also been expelled.
Traces of the illegal steroid stanazolol were found in the 32-year-old PE teacher's system.
The latest results take the number of doping cases in Athens to 20. The previous record had been 12 in Los Angeles in 1984.
The post-event test of Gyurkovics, 24, showed up oxanfrolone, a banned steroid, and the medal positions will change as a consequence of his disqualification.
Ukrainian Igor Razoronov moves up to silver while Russian Gleb Pisarevskiy takes the bronze medal.
World Anti-Doping Agency chief Dick Pound said this week that users of stanozolol - found in Fonseca's system - suffered from "complete arrogance or stupidity" due to the ease of its detection.
It was also the drug for which Ben Johnson tested positive at the Seoul Olympics in 1988.