All 3,773 technological fraud tests at the Tour de France came back negative, the UCI has announced.

Cycling's governing body has stepped up its monitoring of equipment since a concealed engine was detected in Femke Van den Driessche's bike at the Cyclo-cross World Championships in January.

Prior to the Tour - which was won for the third time by Team Sky's Chris Froome - the UCI stressed its intentions to closely monitor bikes throughout the peloton using thermal imaging and x-rays, and over the 21 stages they conducted nearly 4,000 tests.

The UCI says all tests were carried out "unannounced, prior, during or after racing" and that all equipment came back clear.

"I want to thank the UCI staff for its hard work and dedication in testing so many bikes over the past three weeks," said president Brian Cookson.

"This demonstrates our absolute commitment to leave no stone unturned in a matter that if not tackled properly, could seriously damage the renewed reputation of cycling.

"I would also like to thank the riders, the teams, the organiser of this year's Tour, as well as the French police for their co-operation and support. 

"We will continue to test bikes heavily throughout the rest of the season, and do everything in our power to make sure this form of cheating stays out of our sport."