Dr Mike Ashenden, project manager of the international consortium Science and Industry Against Blood Doping, told The Saturday Daily Telegraph that an unreleased study shows how riders can still get away with EPO use four years after testing was introduced for the endurance-boosting protein hormone. "There have been persistent rumours over the past years that athletes have learned to manipulate their EPO injections to escape the urine test," Ashenden said. "We (SIAB) have now replicated this in our own research and we know how it can be done. Our research shows that if an athlete had an expert doctor helping them, it would be possible to use EPO throughout the Tour de France without being found positive. "If the athlete followed the program given by their doctor, the urine samples would be declared negative according to strict criteria used by anti-doping authorities." The research was conducted at the University of Montepellier in southern France and then analysed at the Laboratoire National de Despistage du Dopage at Chatenay-Le Malabry near Paris. It is at the LNDD where the six positive EPO tests of seven-time Tour champion Lance Armstrong from frozen B-samples from the 1999 race were made retrospectively - much to the protest of the Texan who yesterday again denied his guilt to the US public; this time on CNN's Larry King Live. The SIAB research into how EPO use can be manipulated without levels exceeding a legal threshold lasted "three to four weeks". It involved monitoring of a carefully timed and administered program of EPO use on two human guinea pigs or "well trained endurance subjects" who had blood and urine samples taken from them throughout the study. The doses given were similar to what a rider would use in the Tour. They were based on regular low doses that ensured EPO readings fell under the threshold within 12 hours but held the maximum allowed level of haematocrit (oxygen carrying red blood cells) - rather than high doses that can surpass the allowed level and then lead to a positive test. But it did not include the added administering of undetectable drugs like human growth hormone or insulin growth factor which is a widely suspected process that can also heighten the impact of a low dose of EPO. "We boosted their haematocrit and kept it below the allowed 50 per cent," said Ashenden. "Then we reduced the dosage of EPO slowly over a matter of weeks, giving them two or three injections a week. "We monitored their blood to make sure their haematocrit was high. By the end of three or four weeks, the dosage was low but the haematocrit was high." Armstrong used his TV interview to attack the LNDD laboratory's credibility yesterday. "It is absolutely a case of he-said she-said. Do you think I'm going to trust some guy in a French lab to open my samples and say they're positive and announce that to the world and not give me the chance to defend myself? "That's ludicrous. There is no way you can do that," said the Texan, who admits that the accusations are unlikely to go away. (Source: The Daily Telegraph)