Salanson in action for the Bonjour team in 2002

The 23-year-old French rider was found dead in his hotel room in Dresden ahead of this week's Tour of Germany.

Dresden police asked the International Olympic Committee doping laboratory in Kreischa to investigate.

But the lab failed to find any substances that could have contributed to Salanson's death, district attorney Juergen Schaer said on Friday.

Salanson's case is the second mysterious death on the cycling tour this year. In January, Italy's Denis Zanette died of a heart attack while visiting a dentist.

Salanson was widely seen as a rising star in French cycling.

He turned professional in 2000 with the Bonjour team before transferring to Brioches La Boulangere earlier this year.

He won two stage victories, including one at the Grand Prix du Midi Libre in 2002.

Jean-Rene Bernaudeau, Brioches La Boulangere's sporting director, said Salanson had been under normal medical surveillance.

The French team also tried to dismiss fears that doping had been involved in the young rider's death.

Christian Guiberteau, the Brioche team's deputy director, said: "We want everything to be probed to avoid that sort of suspicion."