Tom Dumoulin (Gallo Images)
Saint-Gervais - Tom Dumoulin's Olympic gold medal hopes are under threat after he broke his wrist in a crash at the Tour de France on Friday.
The time-trial specialist had been enjoying a remarkable Tour having won two stages, but it all went wrong on Friday's 19th stage as he crashed out of the race in pain.
"From first x-ray it seems that @tom_dumoulin has a fracture in his left radius. Now scan at hospital and full check up," said his Trek team on Twitter.
Dumoulin faces a race against time to be fit enough to ride the Olympic time-trial in Rio in less than three weeks.
Having won two stages and finished second on Thursday's uphill time-trial, Dumoulin was enjoying a dream Tour, but it all went wrong 60km from the end of the 146km Alpine stage.
Dumoulin, the gold medal favourite for Rio, was sitting comfortably in the peloton but innocuously lost control of his bike and crashed.
When he got up he was holding his wrist and in obvious pain.
He was seen to by race medics and then quit without even trying to ride on.
Dumoulin won a silver medal in the time-trial world championships two years ago.
But he won another race against the clock last week during the Tour on a course with some similarities to the one in Rio.