Formula One legend Michael Schumacher is in a critical condition in a Grenoble hospital after suffering head injuries in a skiing accident in France.
French television station BFMTV and local paper Le Dauphine Libere reported on Sunday the condition of the record seven-times F1 champion has deteriorated.
Schumacher's manager Sabine Kehm had earlier confirmed the 44-year-old German sustained head injuries from the accident in Meribel.
The seven-time German world champion, who reportedly owns property at the resort, was skiing off-piste with other skiers.
A specialist neurosurgeon from Paris has been brought in to oversee treatment of the 44-year-old German in the hospital in the southeastern city of Grenoble.
In initial comments to Radio Monte Carlo Sport, Gernigon-Lecomte had said Schumacher was wearing a helmet and was "conscious but a little agitated" after the accident.
But mountain police who gave first aid to the ex-Formula One driver said he was suffering "severe cranial trauma".
Within 10 minutes, a helicopter airlifted him to a local hospital. When the gravity of his condition became apparent, he was taken to the better-equipped Grenoble facility.
There, doctor Gerard Saillant, a renowned neurosurgeon, was rushed in by police to take charge of Schumacher's treatment.
Schumacher's spokeswoman, Sabine Kahn, confirmed the accident but gave no medical details.
"He was taken to hospital and is receiving professional medical attention. We ask for understanding that we cannot give out continuous information about his health," she said.
"No one else was involved in the fall."
Schumacher reportedly owns property in Meribel. He is to have his 45th birthday on January 3.
A towering figure in Formula One
Schumacher, who won the last of his world titles in 2004, definitively retired in 2012 in the Brazilian Grand Prix, in which he finished seventh, after an abandoned attempt to quit six years earlier.
Since his debut in 1991, the German towered over the sport, winning more Formula One world titles and races than any other. He had a record 91 wins and is one of only two men to reach 300 grands prix.
Schumacher's duels in his heyday with Damon Hill and Jacques Villeneuve, fired by an unquenchable competitive spirit, have gone down in Formula One lore.
Schumacher was born in January 1969 near Cologne, Germany, the son of a bricklayer who also ran the local go-kart track, where his mother worked in the canteen.
By 1987, Schumacher was the German and European go-kart champion and was soon racing professionally. In 1991 he burst into Formula One by qualifying seventh in his debut race in Belgium and a year later he was racing for Benetton, where he won his first Formula One grand prix in 1992.
After joining Ferrari in 1996, Schumacher achieved infamy by trying to ram Villeneuve off the road at Jerez in the last race of 1997, and was disqualified from the championship as punishment.
Over the next decade, he went from strength to strength, dominating the podium, before trying to retire the first time aged 37.
But the father of three could not resist the lure of the track and in 2010 he signed a three-year deal with Mercedes.But slower reflexes and a less competitive car meant Schumacher could not reproduce his former glory and he quit for good in 2012. His helmet had a message for fans: "Life is about passions -- Thank you for sharing mine."