BEIJING (AFP) - Jamaican track and field officials were quick Saturday to scotch any rumours that their star Olympic medalling athletes were doped, saying that more than half of the team had been tested in Beijing. In the face of a misfiring US team, Jamaica has made merry at the National Stadium in the Chinese capital, winning all four sprint titles and the men's 4x100m relay. There have also medalled in the women's 400m flat and hurdles. The charge has been led by Usain Bolt, who set an unprecedented tally of three world records in claiming gold in the 100m, 200m and as part of the 4x100m relay team. The 22-year-old said he had been continually targeted for doping tests. "We've been tested a lot," he said. "I was tested four times (in Beijing) before even running, they took blood and urine tests. "We know we're clean. We work hard. Anytime they want to test it's pretty good for us. "Jamaica's a very proud country. We work very hard to stay on top. We have some serious coaches who really push us to be the best we can." Mike Fennell, president of the Jamaican Olympic Association, argued that Jamaica's track medal haul was indicative of what had started when Arthur Wint won the 400m in the 1948 London Games. "We're the leading athletic country in the world," he said, adding that it was a result of "pure, raw talent that has been properly nurtured. We're reaping the rewards of all that hard work. "We take this anti-doping question very seriously and have done for some years. "We've had testing for some time, and come under the scrutiny of the IAAF," he said, referring to the world athletics' governing body. Jamaican officials carried out more than 90 pre-Olympics tests during the country's national championship and an internationl track meet there, Fennell said. "Athletes competing on the world circuit have been tested as well." Jamaican chef-de-mission Don Anderson added there had been 32 doping tests carried out on Jamaican athletes in Beijing, including three on Bolt, three on former world record holder Asafa Powell and three on women's 100m silver medallist Sherone Simpson. "That's more than 50 percent of our team," he said. "That, as far as I'm concerned, is more than adequate proof (of no doping)." Anderson summed up the upbeat mood of the Jamaican team by saying that an even larger medal haul at the London Olympics in 2012 was now the focus. "These Olympics have been the most successful Olympics to date (for Jamaica)," he said. "It will be very hard to match that. It's been an amazing achievement. But we plan to build on that for London 2012, and in fact surpass that." The Caribbean island's sports minister, Olivia Grange, also had words of encouragement for the track stars. "This is a great day to be sports minister of our wonderful country of Jamaica," she said. "You have lived up to the tradition. Now there's a new beginning because you're going to get better and better as we go forward. "The government has put a lot of emphasis on sport. On my return to Jamaica, we will be pursuing a centre of excellence. "We intend to ensure that the nursery of athletes in Jamaica continues, that we put the proper infrastructure in place so the tradition continues."