French investigators have said that former Formula One driver Michael Schumacher's skiing accident in the French Alps was not due to safety breaches by the ski station or faulty material.

"There were no breaches by anybody. The accident occurred in an off-piste zone," said prosecutor Patrick Quincy.

He added that the markers and other signs at the ski resort of Meribel "conformed to current French laws".

Schumacher has been in intensive care in Grenoble University Hospital since his 29 December accident in which he hit his head against a rock so hard that it cracked his helmet.

After surgery to reduce bleeding and bruising, he was placed in a medically-induced coma and his body temperature lowered to reduce the risk of further damage.

Schumacher's spokesman said on 30 January that the drugs used to keep him in a coma were being reduced with a view to bringing him back to consciousness.

His family said last Thursday that he was "still in a waking up process", which could take a long time.