NOIRMOUTIER, France -- Six-time Tour de France champion Lance Armstrong underwent a surprise dope test at his hotel on Friday afternoon, a control that raised questions as the American was the only rider to be tested.

Tour organizers confirmed on Saturday, at the start of the 11.8-mile first-stage time trial to the island of Noirmoutier, that the American had undergone blood and urine testing in his team's technical area in the car park of the Discovery Channel team hotel in Nantes.

The Texan was the only rider to be tested a second time, two days after blood testing on all 189 Tour starters.

A stone-faced Armstrong told journalists he had been randomly tested six times out of competition this season and added he was under the impression the test had been monitored by the French sports ministry.

But French sports minister Jean-Francois Lamour said on Saturday in Noirmoutier that his agencies were not behind the random test.

"There is an agreement between Tour organisers ASO, the International Cycling Union and the ministry for random testing and the decision to test a rider is made by a medical commission," Lamour said.

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