Bikes will be tested at the Tour de France and Olympics to try to find hidden motors and stop 'mechanical doping', cycling's governing body says.

The UCI says up to 12,000 bikes will be tested this year using a new scanning system introduced in January.

Belgium's Femke van den Driessche was banned for six years last month in the first proven case of mechanical doping.

"If you use this method of cheating, we will catch you," UCI president Brian Cookson said.

The UCI believes that its new system of magnetic resonance scanning, which detects motors, magnets and batteries, is more effective than using heat-seeking cameras.

UCI technical manager Mark Barfield says riders who switch bikes mid-race could be targeted.

Demonstrating its testing technology on Tuesday, the UCI says the one hidden motor found - in Van den Driessche's bike at the Cyclo-cross World Championships in Belgium in January - was at the first event where magnetic resonance scans were used.

Van den Driessche, the former European Under-23 champion, has denied suggestions she deliberately cheated, saying the bike was not hers.

UCI regulations, which were recently strengthened, state 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.