A camera that Michael Schumacher was wearing on his helmet when he was injured in a skiing accident has been handed to authorities, the Formula One champion's manager said.

The racing driver, who suffered a severe head injury while skiing off-piste in the resort of Meribel in France last Sunday, remains in an artificially induced coma.

He is in a critical but stable condition and it is believed his life was saved by his skiing helmet, which split on impact.

Schumacher turned 45 yesterday, with his family saying they were “overwhelmed” by the support of fans who gathered at the Grenoble hospital to mark the occasion.

Sabine Kehm said in a statement that investigators had been given the camera by relatives, dismissing speculation this was against their wishes.

It is not expected there will be a press conference over the weekend, she added. Members of Schumacher’s family arrived at the hospital earlier today to be by his side.

Schumacher was initially conscious after the accident, which happened on a family holiday, but deteriorated into a critical condition. Neurosurgeons have operated twice to remove blood clots on his brain and reduce swelling.

Schumacher retired from F1 for the final time in 2012 after a three-season comeback with Mercedes. Schumacher, who also raced for Jordan, Benetton and Ferrari, won the last of his world titles in 2004.

He won two with Benetton in 1994 and 1995 before moving to Ferrari and winning five in a row from 2000. The German has 91 career wins.