New products may be on the market says French expert

PARIS, Aug 6 (Reuters) Testosterone alone may not explain such astonishing performances as that produced Floyd Landis in the 17th stage of the Tour de France this year, according to a French doping expert.

The 30-year-old American has been sacked by his Phonak team and is likely to be stripped of the Tour title after testing positive for the male sex hormone.

''Testosterone doping is very efficient. It still is common practice because the oral absorption is hard to detect,'' Gerard Dine, a researcher and an expert with the national organization for scientific research, told Reuters.

''In fact, the testosterone is then quickly eliminated by the body. If the test happens a bit late, the substance will not be detected.

''But testosterone itself cannot explain a performance such as Landis's during the 17th stage of the Tour.'' The American rider, who had performed dismally on the previous day in the ascent to La Toussuire, made up for lost time the day after when he won the next stage in Morzine after a 133-km solo effort.

''As he has a prescription for corticoid-based medecine for his hip, the ideal thing would have been to increase the dosage,'' said Dine.

''There are two types of tests for testosterone. The classic one, which shows the ratio of testosterone in the urine to another hormone, epitestosterone. But it does not tell whether the testosterone is natural or synthetic,'' he added.

''The second test, called IRMS (Isotope Ratio Mass Spectometre), determines whether the testosterone is synthetic or not.'' The New York Times quoted a source at the French national anti-doping laboratory in Chatenay Malabry as saying one advanced test had already shown that Landis's testosterone was not naturally produced in his body.

''If there has been a doping offence, it is very likely that there has been ingestion of a doping cocktail of testosterone with substances which we don't know about yet,'' said Dine.

''But if the testosterone is found to be natural, the most likely scenario is that a 'THG type designer steroid' -- but not THG itself -- has been used.

''In such cases, the natural level of testosterone increases.'' REUTERS AY RAI1447