ATHENS: It was not until 1967 that the International Olympic Committee (IOC) banned drug use at Olympics. This was prompted in part by the death of Danish cyclist Knut Jensen during the road race at the 1960 Games after taking amphetamines.

Full-scale drug-testing was introduced in 1972.

Anabolic steroids, strength-building drugs that mimic the effect of the male hormone testosterone, were banned in 1976 after a test for their use was developed in 1974.

In the struggle between Olympic officials on the one side, and athletes, doctors and coaches on the other, positive drug tests hardly reflect the scale of the doping problem.

In addition to out-of-competition positive tests, there is evidence of a far more systematic abuse of the system.

Between 1970 and 1989, victims' groups estimate up to 10,000 East German athletes were routinely doped with anabolic steroids such as turabinol. During this time, the East Germans collected 570 Olympic medals.

MEXICO 1968

- Hans-Gunnar Liljenvall of Sweden became the first Olympic athlete to be disqualified for drugs after he failed a breath test for alcohol in the modern pentathlon's shooting stage.

MUNICH 1972

- Sixteen-year-old US swimmer Rick DeMont was stripped of his gold medal in the 400 metres freestyle. Blame fell on team physicians after it emerged DeMont had taken a cough medicine he did not realize contained the banned drug ephedrine.

- Mongolian lightweight Bakhaavaa Buidaa lost his silver medal after becoming the first person in judo history to fail a drugs test.

- The Dutch time-trial cycling team lost their third place when member Aad van den Hoek tested positive for coramine, a drug allowed by the International Cyclists' Union but not the IOC. Spanish cyclist Jaime Huelamo was also stripped of a bronze medal in the road race.

- Drug tests showed 14 modern pentathletes had taken tranquilizers before going on to the shooting range. The drugs were banned by the sport's governing body but not by the IOC, so no disqualifications were made.

MONTREAL 1976

- The first Olympics since steroid tests were developed resulted in a slew of weightlifting disqualifications.

- Polish lightweight Zbigniew Kaczmarek of Poland and Bulgarian heavyweight Valentin Hristov finished in gold medal position before being stripped of their titles.

- Czech Petr Pavlasek, Bulgarian Blagoi Blagoev, and Philip Grippaldi and Mark Cameron of the United States were also disqualified.

MOSCOW 1980

- No athletes were disqualified for failing a drug test at the Moscow Olympics.

LOS ANGELES 1984

- Finnish runner Martti Vainio became the highest-profile disqualification to date when he was stripped of his 10,000 metre silver medal for testing positive for anabolic steroids.

- Swedish super-heavyweight Greco-Roman wrestler Thomas Johansson lost his silver medal after a positive steroids test (he won bronze in 1988). Heavyweight weightlifting compatriot Goran Pettersson was also disqualified.

- Weightlifters from Austria and Lebanon were disqualified as was fourth-placed Italian hammer thrower Giampaolo Urlando, who tested positive for testosterone.

SEOUL 1988

- The best-known doping case in Olympic history occurred when Canadian sprinter Ben Johnson, who ran faster than any man in history to win the 100 metres in 9.79 seconds, was stripped of his gold. US rival Carl Lewis was awarded the winners' medal after Johnson tested positive for steroids.

Johnson initially denied taking steroids but later admitted to a seven-year-long drug regime, including steroids, hormones, and masking agents.

- Bulgaria had won four golds and one silver medal in weightlifting before bantamweight gold Mitko Grablev and lightweight gold Angel Guenchev tested positive for a diuretic used as a masking agent for steroids. The Bulgarians withdrew the rest of their team.

- Two Hungarian weightlifters were also disqualified.

BARCELONA 1992

- Fourth-placed Jud Logan in the hammer and shot-putter Bonnie Dasse were disqualified after testing positive for clenbuterol, a German asthma medication officially classed as an anabolic steroid.

- Chinese volleyball player Wu Dan was thrown out after taking a Chinese folk tonic that, unknown to her, contained the stimulant strychnine.

ATLANTA 1996

- The Games' only positive test results came from a Lithuanian cyclist and four Russians - two swimmers, a sprinter and a wrestler - who tested positive for the banned stimulant bromantan.

All five had their results reinstated after the Court of Arbitration for Sport (CAS) ruled there was insufficient evidence to disqualify them.

SYDNEY 2000

- Positive steroid tests led to the disqualification of Norwegian and German wrestlers, a Latvian rower and an Armenian weightlifter. Three Bulgarian weightlifters also tested positive for a diuretic.

- Romanian gymnast Andreea Raducan lost her gold when she tested positive for pseudoephedrine, a banned drug contained in an over-the-counter cold remedy. Raducan's appeal to CAS failed but pseudoephedrine, along with caffeine, has since been removed from the Olympics' banned list.

- Eleven athletes in total tested positive.

ATHENS 2004

- Top Greek sprinters Costas Kenteris and Katerina Thanou withdrew after failing to take pre-Games drug tests. They apologized to the Greek people but insisted they were innocent.

- World 100 metres champion Torri Edwards' appeal against a two-year drugs ban was dismissed by the Court of Arbitration for Sport (CAS), ending her bid to compete at the Olympics. She tested positive for the stimulant nikethamide.

- Women's shot put champion Irina Korzhanenko of Russia tested positive for a steroid. Two other champions, hammer thrower Adrian Annus and discus thrower Robert Fazekas, both of Hungary, were forced to hand back their golds for anti-doping violations without testing positive.

- Nineteen athletes tested positive during the Games and five were banned for breaking anti-doping regulations.

(China Daily 09/01/2004 page15)