Belgian rider Femke van den Driessche has been suspended for six years in the first proven case of mechanical doping in cycling.
Cycling's governing body the UCI found the 19-year-old's spare bike contained a motor at January's Cyclo-cross World Championships in Belgium.
Van den Driessche has also been fined 20,000 Swiss francs (£14,000) and been ordered to pay legal costs.
The former European Under-23 champion must also return all her medals.
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The result of the World Championship race, the women's under-23 race won by Great Britain's Evie Richards, is not affected.
Scanning of bikes in UCI competitions has been introduced in recent years, but Van den Driessche's was the first found to contain a concealed motor.
There were 274 bikes scanned at the Track Cycling World Championships in London in March.
UCI regulations, which were recently strengthened, state that a rider is given a minimum suspension of six months and a fine of up to 200,000 Swiss francs (£141,000) for an offence of "technological fraud", while coaches, mechanics and other officials could also be sanctioned.
Van den Driessche was competing during the women's under-23 race at the Cyclo-cross World Championships. The motor was hidden, along with a battery, in the tube below the saddle. It was controlled by a Bluetooth switch installed underneath the handlebar tape.
She has denied suggestions she deliberately cheated, saying the bike was not hers.
"It was my friend's and was identical to mine. 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 told Belgian television in January.