Brian Cookson, the president of cycling's world governing body the UCI, has vowed to stamp out motorised doping after a bike was confiscated at the Cyclo-cross World Championships in Belgium on Saturday for containing a motor.
An incident of "technological fraud" is being investigated in the under-23 women's race, which was won by Great Britain's Evie Richards.
None of the podium finishers from the race at Heusden-Zolder are under suspicion.
The UCI issued a press release on Saturday evening announcing the bike had been detained and on Sunday morning Cookson confirmed the first case of mechanical doping in a sport which is trying to recover from the spectre of performance-enhancing drug use.
"It is no secret that a motor was found," Cookson said during a media conference, as reported by cyclingnews.com.
"We believe that it was indeed technological doping."
Cookson added on Twitter: "Technological fraud is unacceptable.
"We want the minority who may consider cheating to know that, increasingly, there is no place to hide, and sooner or later they will pay for the damage they're causing to our sport."
Bikes have been scanned by the UCI at major competitions, including the Tour de France, in recent years after rumour and speculation regarding motors hidden in frames.
But this is the first time a motor has been discovered.
Regulations, recently strengthened, state that a rider is given a minimum suspension of six months and a fine of up to 200,000 Swiss francs for an offence of "technological fraud".
Belgian media outlet Sporza reported that the Belgian federation had confirmed that the detained bike belonged to Femke Van den Driessche.