SAINT-ETIENNE, France -- French customs agents looking for doping products stopped, searched and released a car driven by the father of Tour de France riders Frank and Andy Schleck on Thursday, officials said.
The agents carried out the random search near the city of Grenoble along the route of the 18th stage and didn't find any doping products or other illegal products, a customs spokesman said.
"Two vehicles were searched: one in which nothing was found; and from the other -- the one of Frank Schleck's father -- some products were taken for verification," said Raphael Grandfils, a state prosecutor in Grenoble. "It turns out that this was not about forbidden products, but medicines that are totally normal to possess."
Johnny Schleck was allowed to return to the course route, the customs spokesman said, adding that it was a random check -- one of many carried out during the three-week event. He said two vehicles were stopped and released.
Both Schleck brothers have undergone anti-doping tests frequently during the race, both at the finish and in surprise visits by French anti-doping authorities. Each was tested every day from Sunday through Wednesday.
Frank Schleck trails CSC teammate Carlos Sastre of Spain by 1 minute, 24 seconds in second place after Thursday's 18th stage.
CSC has performed impressively at the Tour, controlling much of the action in the mountains by sending aggressive riders like Jens Voigt, Fabian Cancellara and Andy Schleck to the front to ride tempo. Frank Schleck earned the yellow jersey in a rugged Alps stage that crossed the Italian border and wore it through Wednesday.
Sastre leads the race courtesy of his breakaway attack on Alpe d'Huez. Andy Schleck is currently wearing the white jersey awarded to the Best Young Rider -- the under-25 rider with the lowest cumulative time. CSC-Saxo Bank also is in first place in the team classification.
A rowdy, cheering group of fans with banners greeted Frank Schleck as he rolled up to the team bus after Stage 18.
Team owner and director Bjarne Riis appeared smiling and relaxed when he talked to successive waves of reporters in Spanish, French, German, Danish and English, and said he intended to keep the atmosphere "calm."
"We're here to get results and do some good things,'' Riis said. "There's nothing to be upset about. The police do their job and we do ours. That's it. We have nothing to fear."
Riis added that he is happy his riders are being tested often.
Information from ESPN.com reporter Bonnie D. Ford and The Associated Press was used in this report.