The seven-time F1 world champion remains in a critical condition following a skiing accident in the French Alps on Sunday

Doctors operating on Michael Schumacher following his skiing crash said the F1 star would be dead by now had he not been wearing a helmet.

The seven-time Formula One champion is in an induced coma in intensive care at the University Hospital of Grenoble, after hitting his head on a rock in a crash on Sunday in the resort of Meribel in the French Alps.

The 44-year-old remains in a critical condition, with injuries described as life-threatening.

Doctors treating Schumacher, who retired from Formula 1 for the second time in 2012, said at a press conference they could not speculate on his prognosis.

However, the did say that without his helmet he would already be dead.

They said: "We believe that taking into consideration the very violent shock, his helmet did protect him to a certain extent.

"Someone who would have had this accident without a helmet, he would certainly have not got to here."

Doctors said the brain scan Schumacher underwent on his arrival at the hospital showed "a great number of lesions".

The former Ferrari and Mercedes driver is receiving treatment to reduce the pressure on the brain.

"The brain scan showed some intracranial haematoma, but also some cerebral contusions and edema," added Doctors.

"We operated urgently to try and eliminate the haematoma. After the operation we saw that we had been able to eliminate the haematoma, but also sadly the appearance of various bilateral lesions and so therefore he was taken to intensive care to try to help him.

"His condition is critical as far as cerebral care. All the recommended treatments have been introduced."

Schumacher’s wife, Corinna, and their two children, were at his bedside, doctors said.

Schumacher, 44, was skiing at the Meribel resort with his 14-year-old son when the accident happened on Sunday morning. The teenager was unharmed.