Great Britain's Liam Killeen has crashed out of the Olympic cross-country mountain bike event at Hadleigh Farm in Essex.
The 30-year-old from Malvern finished fifth in Athens and seventh in Beijing, but started in 25th place on the grid.
Killeen was being treated by medical staff on the course at the foot of Deane's Drop, a steep section of boulders on the 4.7-kilometre route, on the second lap of seven.
British Cycling reported Killeen had sustained a suspected broken ankle.
An ambulance was set to take Killeen to Homerton Hospital.