A Bulgarian weightlifter lost his gold medal and an Australian athlete was expelled from the Games Thursday in the first cases of banned drugs being detected at the Seoul Olympics.

The action gave the gold medal in the 56-kilogram (123.2-pound) weightlifing division to a Soviet and the silver and bronze to Chinese.The International Olympic Committee said tests showed Bulgarian Mitko Grablev took a banned diuretic "aimed at reducing weight," and Australian Alexander Watson, competing in the modern pentathlon, had excess levels of the stimulant caffein in his urine.

After the IOC Executive Board disqualified both athletes from the current Games and withdrew Grablev's gold medal, the International Weightlifting Federation added a two-year suspension from international competition.

Further action against Watson was not expected until the International Union for the Modern Pentathlon and Biathlon general assembly meets in Italy in November.

Officials said before the Seoul Games began that they expected about 15 positive drug tests among the 10,000 competitors, up from 12 in 1984.

Grablev's triumph, with an Olympic record total of 297.5 kilograms (6553/4 pounds), was one of three gold medals won by Bulgarian weightlifters.

Gotfried Schodl, president of the international federation, said tests on the other Bulgarian winners did not show any banned drugs.

Schodl said at a news conference Thursday night that a new medal ceremony was planned for Saturday, with the gold going to Oxen Mirzoian of the Soviet Union for his total lift of 292.5 kilograms (6431/2 pounds) . The silver goes to China's He Yingqiang for his 287.5 (6321/2 pounds) and the bronze to his teammate Liu Shoubin, whose total was 267.5 (5881/2 pounds).