Aurillac - Russian cyclist Alexandr Kolobnev became the first rider to be forced out of the Tour de France on Monday after an 'A' sample from the Katusha rider tested positive for a banned substance.
A statement from cycling's governing body the UCI (International Cycling Union) announced that a urine sample taken from Kolobnev in-race on July 6, had tested positive for Hydrochlorothiazide.
Following the news which came on a rest day his team reacted quickly, pulling their man out of the race.
"We have decided to take Alexandr Kolobnev out of the Tour de France," Katusha sporting director Dimitri Konyschev announced at the team's hotel.
The UCI, confirming the rider's positive test, issued a statement reporting: "The UCI has informed the Russian rider Alexandr Kolobnev of an abnormal finding (presence of Hydrochlorothiazide according to a report submitted by the WADA-accredited laboratory in Chatenay-Malabry) from a urine sample taken during the Tour de France on July 6, 2001.
"M. Kolobnev has the right to request analysis of a B sample and to be present during the process."
Under UCI rules Kolobnev could have continued to race because the banned diuretic is classed as a "specific substance" by the UCI.
The statement added: "The UCI's anti-doping rules do not foresee a provisional suspension given the nature of the substance, which is a 'specified substance'.
"However the UCI is confident that his team will take the necessary measures to ensure the serenity of the Tour de France and at the same time give the rider a chance to prepare his defence, notably with respect to the reglementary four day period in which he is obliged to proceed with the analysis of a B sample."
Katusha, in a bid to save the Tour and the team from further controversy, said Kolobnev would quit the race.
The Russian outfit said he would be sacked if the B sample was also positive.
"Team Katusha rider Alexandr Kolobnev, after testing positive for a diuretic at a medical examination during the Tour de France’s first week, decided to suspend himself according to UCI rules, waiting for the B-sample," said Katusha's statement.
"At the moment, Team management and the rider have no further comment. It has to be noticed that internal rules in Team Katusha say that the rider, if the B-sample also tests positive, will be fired and will have to pay five times his salary as a fine."
After the news broke Kolobnev was seen leaving his team hotel in nearby Vezac in one of two Katusha team cars which were being escorted away by two police cars.
In one of the team cars was Katusha's chief Andrei Tchmil.
"The President of the sport group Andrei Tchmil went voluntarily to the police, together with Kolobnev and his room-mate (Egor) Silin, in order to translate and reinforce the fact that he and the team are not involved to the contested facts."
A diuretic, hydrochlorothiazide is listed as a banned substance because it can also be used to mask other drugs.
The 30-year-old Kolobnev, a silver medal winner at the 2009 world road championships, was placed 69th in the overall Tour de France standings, 22min 15sec behind yellow jersey leader Thomas Voeckler.
Kolobnev, a multi national champion, is also a respected one-day classics rider who finished fourth in the Olympic road race in Beijing at the 2008 Games.
He has also finished on the podium of several hilly classics, finishing third in the Tour de Lombardy in 2009, sixth at the Amstel Gold Race the same year and runner-up at Liege-Bastogne-Liege in 2010.
Australia's former top cricket star Shane Warne tested positive for Hydrochlorothiazide along with amiloride in February 2003, prompting him to pull out of the World Cup.
He was given a 12-month ban by the Australian Cricket Board's anti-doping unit.