Reigning Olympic 100m champion Maurice Greene called for an investigation into allegations that prominent US Olympians, like Carl Lewis, failed drug tests in the build-up to the 1988 Seoul Games.“Everybody who tested positive should get busted. There shouldn’t be any cover-ups,” said Greene at the Mount San Antonio College relays yesterday where he won the 200m.The charges, reported this week in Sports Illustrated, the Daily Telegraph in London and the Orange County Register, came in documents released by former US Olympic committee anti-doping official Dr Wade Exum.Exum’s papers indicated Lewis was one of 19 prominent American athletes who tested positive but were still allowed to compete in South Korea.Lewis was awarded the gold medal in Seoul in the 100m after Canadian Ben Johnson was stripped of his victory for failing a dope test after the race. Johnson tested positive for the steroid stanozolol.“It is terrible,” Greene said. “It is hurting our sport in general . not just in the United States but in general.“It is a bad thing.”According to Exum’s documents, Lewis was one of three eventual gold medallists who tested postive for banned stimulants at the 1988 Olympic trials in Indianapolis. It was claimed Lewis gave three urine samples containing pseudoephedrine, ephedrine and phenylpropanolamine.American runner Terry Evens said yesterday that he was stunned by the claims against Lewis, who won nine Olympic gold medals in a glittering career.“I heard about it last night when a couple of guys were sitting around talking,” said Evens, who competed in a relay at Mt. Sac. “I was shocked. It left me speechless. I still look up to Carl.”Joe Deloach, who won the 200m, and Andre Phillips, who won the 400m hurdles, also tested positive for a banned stimulant in 1988.None was prevented from competing after the US Olympic committee determined they had ingested the substances inadvertently.Floyd heard trained with Lewis and, according to Exum’s documents, tested positive in 1988 for the same three substances. Heard did not make the US team that year and said yesterday he can’t remember ever getting a letter telling him he tested positive.“That was 1988. Now it is a big deal because (Exum) got fired and he wants to come up with all these lies,” he said.