Argentine motorcyclist Jorge Martinez Boero was killed when he crashed on the first stage of the Dakar Rally in Argentina.
Boero, 38, crashed near the end of the special section among dunes on the Atlantic coast on his Beta RR450 on the stage from Mar del Plata in Buenos Aires province to Santa Rosa in La Pampa in the centre of the country.
The son of a former national motor racing champion and taking part in his second Dakar rally, he suffered serious injuries to his thorax and cardiac arrest.
"The rider suffered a cardiac arrest following his fall and was attended five minutes after the accident by the medical staff, who reached the place of the incident by helicopter," said a statement on the official race website.
"Despite their best efforts, the doctors were unable to resuscitate the pilot (rider), who died while he was being taken to hospital."
The rally, which moved from Africa to South America for security reasons four years ago, is notoriously dangerous and has claimed several lives in the past.
"However experienced the racers may be, they know the Dakar is high risk and that unfortunately this (kind of accident) can happen. Any error can cost you your life," Ignacio Crotto, race coordinator for the province of Buenos Aires, told TN television news.
Boero made huge efforts to be able to take part, including selling his apartment having had to pull out last year after getting lost on the fifth stage in the Atacama Desert in northern Chile.
"I'm going to give it everything to get to Lima... What doesn't kill (you), strengthens you," he told friends and family on what was to be his last ever message on his twitter account (jmboero)
More than 20 competitors have lost their lives since the first Paris-Dakar rally in 1979 with Boero the second in Argentina after Frenchman Pascal Henry in 2009.
There have also been numerous deaths among spectators, organisers including race founder Thierry Sabine and members of the media.
During last year's race a man died after his car was hit by another taking part in the rally and in 2010 a woman watching the rally died after being hit by a participating vehicle.
In the years the race was held in western Africa, there was often the threat from gangs or bandits, finally the cause for the race to be moved to South America.
Previously raced in Argentina and Chile, this year's rally has been extended to include Peru and covers a distance of nearly 9000 km, finishing in Lima on January 15.