Alberto Contador was totally relaxed despite French prosecutors opening a preliminary investigation after suspicious medical material was seized during the Tour de France, the Tour de France champion said earlier today.

A source close to the investigation specified on Tuesday that police were particularly interested in Contador's Astana team but the Spaniard was unfazed about the probe.

"In France, the fight against doping is total and Astana was the most scrutinized team in the Tour," Contador told reporters after the route for the 2010 race was unveiled in Paris.

"I heard they were looking into our waste but I'm absolutely relaxed," he added.

Seven times Tour winner Lance Armstrong, who came out of retirement to finish third overall with Astana this year, said: "I don't have any answers because I don't know anything about the case.

"But I'm confident that our team has been racing clean. We just have to deal with it and get on with it."

The investigation was opened after syringes and transfusion material were found in a container used by the Kazakh-funded team to dump medical waste during the last four stages of this year's race.

Under French law, a preliminary investigation is launched to see if there are sufficient grounds for a formal investigation.

The French anti-doping agency (AFLD) said earlier this month a report on testing procedures during the 2009 Tour suggested Astana were given preferential treatment during the race.

Team Astana and the International Cycling Union (UCI) dismissed the suggestions as groundless.