There were no positive doping tests during July's Tour de France, the Cycling Anti-Doping Foundation said on Tuesday.
Director Francesca Rossi stopped short of claiming the Tour had been clean but said 622 samples, including 443 blood samples and 179 urine samples, were taken during the last edition of the world's biggest and most popular bicycle race.
"We have no adverse analytical findings," said Rossi from the International Cycling Union's base.
"We changed the strategy. We were unpredictable and the riders perceived we were unpredictable."
During the Tour, the eventual winner, Britain's Chris Froome, was subjected to intense press scrutiny and speculation regarding the validity of his at times phenomenal performances.
But Rossi was unequivocal about the Team Sky leader.
"We tested him a lot," she said.
Rossi praised the French Anti-Doping Agency for their collaboration.
The news will come as a welcome boost to a sport that has suffered huge damage to its reputation this year with Lance Armstrong's January admission that he cheated throughout his seven Tour victories, of which he has been stripped.
In July the French senate released the names of a number of riders whose retroactively tested samples from the 1998 and 1999 tours had tested positive for banned blood-booster EPO.
Among the names to be revealed were former Tour winners Marco Pantani, now deceased, and Jan Ullrich, who in June finally admitted to his doping past, as well as past sprint king Erik Zabel, who subsequently also came clean.