The International Cycling Union said the bike belonged to 19-year-old Belgian Femke Van den Driessche.
Update (Monday, 8:05 a.m. ET): The AP reports that Italian manufacturer Wilier Triestina says it will sue Van den Driessche.
It is the first official case of "mechanical doping" or "bike doping" at cycling's highest level. If used at the right time during a race even a small motor can provide a critical burst of power and speed.
For years there has been speculation in cycling that motorized cheating might be happening at the sport's highest professional level, but it has never been revealed until now.
"It's absolutely clear that there was technological fraud — there was a concealed motor," UCI President Brian Cookson told a news conference, AFP reported.
The rider, Van den Driessche, was among the race favorites but was forced to withdraw from the women's under-23 event because of a mechanical problem. Belgian news site Sporza reported that there were "electrical cables" seen coming out of the bike.
'It wasn't my bike'
Van den Driessche denied she had used a bike with a concealed motor on purpose, saying that it was identical to her own but belonged to a friend and that a team mechanic had given it to her by mistake before the race, AFP reported.
"It wasn't my bike — it was that of a friend and was identical to mine," a tearful Van den Driessche told Sporza, AFP reported. "This friend went around the course Saturday before dropping off the bike in the truck. A mechanic, thinking it was my bike, cleaned it and prepared it for my race," she added, insisting that she was "totally unaware" it was fitted with a hidden motor.
"I feel really terrible. I'm aware I have a big problem. (But) I have no fears of an inquiry into this. I have done nothing wrong," she added. AFP also reported that Belgian coach Rudy De Bie said he was "disgusted."
"We thought that we had in Femke a great talent in the making but it seems that she fooled everyone," he told Sporza. Sven Nys, a veteran of cyclocross and one of its best riders, said he was shocked and disappointed.
So I photographed moto-cross
"We've heard some stories for a long time now about the possibility of this. We have been alive to a potential way that people might cheat and we have been testing a number of bikes and a number of events for several months," Cookson said, according to AFP.
"I am committed and the UCI is committed to protecting the riders who do not want to cheat in whatever form and to make sure that the right riders win the race. We have been looking at different methods of testing this kind of technology and we tested a number of bikes yesterday and one was found.
Cookson said that the matter would next go before the UCI's disciplinary commission.
Here come the lawsuits
Bike manufacturer Wilier Triestina's managing director, Andrea Gastaldello, said he was "stunned" by the news that Van den Driessche competed with a concealed motor in her Wilier Triestina bike, AP reported Monday.
"Our company will take legal action against the athlete and against any (person) responsible for this very serious matter to safeguard the reputation and image of the company," the said.
We are literally shocked, as the main technical partner, we want to distance from this act absolutely contrary to the basic values of our company, and with the principles of each sporting competition. Really unacceptable that the photos of our bike is making the rounds of the international media due to this unpleasant fact. We work every day to bring worldwide the quality of our products and when we know that a Wilier Triestina’s bike is meanly tampered we’re very sad. Our Company will take legal action against the athlete and against any responsible for this very serious matter, in order to safeguard the good name and image of the company, marked by professionalism and seriousness in 110 years of history.
A Sporza journalist, Renaat Schotte, posted this photo on Instagram on Sunday. It apparently shows an official checking a different bike for technological fraud with a tablet device:
Call for 'lifetime suspension'
Etixx team manager Patrick Lefevere called for a "lifetime suspension for the cheat."
"I never thought that such schemes were possible. It's a scandal that Femke's entourage have deceived the Belgian federation," he said.
The news is a fresh blow to a sport still recovering from the Lance Armstrong doping scandalafter the disgraced American cyclist admitted to cheating throughout his career in 2013 following years of denials and ruthless attacks on his accusers, AFP noted.
Here are the UCI rules and penalties regarding technological fraud (PDF):
When asked by 3m360 about the inspection in Richmond, the UCI replied:
The Union Cycliste Internationale (UCI) takes extremely seriously the issue of technological fraud such as concealed electric motors in bikes, and has therefore added far-reaching sanctions in its Regulations. We have been carrying out controls for many years and although those controls have never found any evidence of such fraud, we know we must be vigilant. We have carried out several unannounced checks on this year’s Tour de France and other Grand Tours. The 2015 UCI Road World Championships in Richmond is the latest event where bikes have been controlled this season, including all top 3 riders of each race. These are extensive controls and nothing was found.
No motor was found in Kiryienka's bike.
This video by CyclingTips features Greg LeMond, the only American to win the Tour de France, showing how one version of a bike motor works:
There are videos on YouTube that purport to show images of mechanical doping, and show that the matter goes back some time. This clip, for instance, shows Canadian Ryder Hesjedal's bike after he crashed at the 2014 Tour of Spain. His rear wheel appears to keep spinning after the crash, so much so that it whips the bike around on the ground after he comes to a stop: