Bulgaria's Olympic weightlifting champion Galabin Boevski was arrested at Sao Paulo's international airport after trying to board a plane bound for Spain with nine kilogrammes of cocaine.
Boevski, who won gold at the Sydney Games in 2000, was stopped by Brazilian anti-drugs officers on and the cocaine was found in his luggage.
He faces up to 15 years in jail.
Boevski was banned for eight years for doping by the International Weightlifting Federation in 2004 after tampering with his urine sample at the 2003 world championships.
It was the second time he had committed a doping office since 1995.
The Bulgarian, 37 in December, also won gold at the world championships in 1999 and 2001, and at the European championships in 1999, 2002 and 2003.