A spokesperson for Michael Schumacher says the 44-year-old was trying to help a friend when he suffered the skiing accident which has left him in a coma.

The former Formula 1 World Champion remains in a critical condition in hospital and has undergone brain surgery - with doctors saying his condition has improved 'slightly' over the past day.

Schumacher's spokesperson Sabine Kehm has denied the German was skiing at high speed and lost control.

She says he went to help a friend who had fallen - before hitting a rock and being catapulted into the air and landing head first.

Kehm also said that his condition remained 'stable' overnight:This fan is one of hundreds who have been offering their support outside the hospital:Michael Schumacher's agent has said his condition has remained stable overnight in a Grenoble hospital after a skiing accident.

Speaking to reporters outside the hospital, Sabine Kehm said: "Michael's condition has been supervised all the night and has remained stable over the night and also now.

"The good news for today is we do not have the feeling to hold a press conference because there's no significant changes."

The German former Formula One driver, who turns 45 on Friday, suffered critical head injuries when he fell and struck a rock on Sunday while skiing on a family holiday in the French Alps.

The slope in Meribel, France, where the accident took place

He was taken first to a local hospital, then to Grenoble University Hospital which is recognised as having one of France's best neurology teams.

He remains in a medically induced coma after undergoing a second surgery on Monday night after a brain scan showed small, "surprising" signs of improvement. His body temperature has also been lowered to between 34 and 35 degrees Celsius to reduce swelling in his brain.

Gerard Saillant, a surgeon and friend of the family who is in Grenoble, said: "We cannot tell you any more about the future."

His agent confirmed that the accident cracked his helmet, which doctors credited for giving him a chance of surviving.

Earlier, Ms Kehm said: "It looks like probably that initiating a corner, he was hitting a stone which he had not seen and was catapulted down on a rock.

"That is extremely and very unfortunate... really very, very bad luck. Michael was not at high speed."

Schumacher retired from F1 last year after winning seven world titles.