Spanish motorbike rider Cristobal Guerrero fell into a coma after crashing during the 10th stage of the Dakar rally across the Atacama desert.
The 48-year-old was rescued and airlifted by helicopter to hospital in the town of Copiapo.
"He is in a coma and has been taken to hospital where he will undergo a scan," said a spokesman for the organisers.
The race, held in South America for the first time, has claimed the life of French motorcycle rider Pascal Terry.
The 49-year-old was found dead three days after going missing.
British driver Paul Green and navigator Matthew Harrison were also left with thorax and spine injuries when their car overturned during the first stage.
The race started in Buenos Aires on 3 January and finishes back in the Argentine capital on 17 January.
Source:
http://news.bbc.co.uk