Story highlights Investigators examine a camera that was attached to Michael Schumacher's ski helmet

The former racing driver remains in critical but stable condition, his manager says

Schumacher suffered severe head injuries in an accident in the French Alps last weekend

He remains in an induced coma in a hospital in the French city of Grenoble

Investigators are studying the camera that was on former world champion driver Michael Schumacher's ski helmet for clues to the cause of a skiing accident that left him critically injured in a French hospital.

French media reports late Friday suggested police had seized the camera from Schumacher's family. It's not yet clear whether it was filming at the time of the accident.

But his manager, Sabine Kehm, said in a statement Saturday that the family had handed the helmet camera over to the authorities voluntarily.

"That this should have been done against the wishes of the family is untrue," she said.

Kehm said Schumacher's condition remains critical but stable.

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Photos: Formula One champion Michael Schumacher Photos: Formula One champion Michael Schumacher Michael Schumacher's manager expressed the "continued support and patience" being offered to the stricken Formula One star. "We must hope that with continued support and patience he will one day be back with us," Sabine Kehm said. In December 2016 she added Schumacher's health "is not a public issue." Hide Caption 1 of 18 Photos: Formula One champion Michael Schumacher Formula 1 champion Michael Schumacher – The seven-time Formula One champion was hospitalized December 29 after suffering "severe head trauma" from a ski accident in the French Alps. He is no longer in a coma and has since been transferred to a hospital in Lausanne, Switzerland for rehabilitation. Here's a look back at his personal and career highlights on the 20th anniversary of his first world title triumph. Hide Caption 2 of 18 Photos: Formula One champion Michael Schumacher Formula 1 champion Michael Schumacher – Schumacher is hoisted by his pit crew at the Australian Grand Prix track in Adelaide, Australia, after winning the Formula 1 World Drivers Championship in 1994. Hide Caption 3 of 18 Photos: Formula One champion Michael Schumacher Formula 1 champion Michael Schumacher – Schumacher holds up the victory trophy, left, and the French Republic President's trophy after winning the French Formula 1 Grand Prix in Magny Cours, France, in 1995. Hide Caption 4 of 18 Photos: Formula One champion Michael Schumacher Formula 1 champion Michael Schumacher – Schumacher meets Pope John Paul II in 1999. Hide Caption 5 of 18 Photos: Formula One champion Michael Schumacher Formula 1 champion Michael Schumacher – King Juan Carlos of Spain congratulates Schumacher after he won the Spanish Formula 1 Grand Prix in 2001. Hide Caption 6 of 18 Photos: Formula One champion Michael Schumacher Formula 1 champion Michael Schumacher – Schumacher checks out an Enzo Ferrari at Frankfurt's International Motor Show in 2003. Hide Caption 7 of 18 Photos: Formula One champion Michael Schumacher Formula 1 champion Michael Schumacher – Schumacher steers his Ferrari in front of a Eurofighter on the track of a military airport in Grosseto, Italy, in 2003. Hide Caption 8 of 18 Photos: Formula One champion Michael Schumacher Formula 1 champion Michael Schumacher – Schumacher sits in his car before the start at the inaugural Chinese Grand Prix in 2004 in Shanghai. Hide Caption 9 of 18 Photos: Formula One champion Michael Schumacher Formula 1 champion Michael Schumacher – A man rides past a poster with Schumacher's likeness in Bahreman, Iran, in 2005. Hide Caption 10 of 18 Photos: Formula One champion Michael Schumacher Formula 1 champion Michael Schumacher – Felipe Massa hugs Schumacher after Massa won first place in the Formula 1 Grand Prix of Turkey in Istanbul in 2006. Hide Caption 11 of 18 Photos: Formula One champion Michael Schumacher Formula 1 champion Michael Schumacher – Schumacher drives during a practice session at the Australian Formula 1 Grand Prix in Melbourne in 2006. Hide Caption 12 of 18 Photos: Formula One champion Michael Schumacher Formula 1 champion Michael Schumacher – Schumacher celebrates his win at the Formula 1 Grand Prix of Germany in 2006 in Hockenheim, Germany. Hide Caption 13 of 18 Photos: Formula One champion Michael Schumacher Formula 1 champion Michael Schumacher – Schumacher's pit team works on his car during the Formula 1 Grand Prix of China in Shanghai in 2006. Hide Caption 14 of 18 Photos: Formula One champion Michael Schumacher Formula 1 champion Michael Schumacher – Schumacher arrives for an awards ceremony in Oviedo, Spain, in 2007. Hide Caption 15 of 18 Photos: Formula One champion Michael Schumacher Formula 1 champion Michael Schumacher – Schumacher autographs the T-shirt of an earthquake victim in Costa Rica in 2009. Hide Caption 16 of 18 Photos: Formula One champion Michael Schumacher Formula 1 champion Michael Schumacher – Shumacher presents the new Mercedes SLS AMG, also the 2010 Formula 1 safety car, in Geneva in 2010. Hide Caption 17 of 18 Photos: Formula One champion Michael Schumacher Formula 1 champion Michael Schumacher – Schumacher visits the European Parliament in Strasbourg, France, to test eSafety technologies in 2011. Hide Caption 18 of 18

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His doctors say no further update on his condition is expected before Monday, Kehm said.

Schumacher suffered severe head trauma in the accident last Sunday in Meribel, in the French Alps. He is in a medically induced coma and has undergone two operations.

Kehm said Tuesday that friends and family who were skiing with him say he hit a rock hidden under deep snow and was catapulted head first onto another rock. He was not moving fast at the time, she said.

Friday was the former Formula 1 champion's 45th birthday, marked with a silent vigil by fans who gathered outside the hospital in the city of Grenoble where he is being treated.

Schumacher, the most successful driver in Formula 1 history, won 72 Grand Prix races between 1996 and 2006 for Ferrari. The automaker posted a message on its website Friday.

"This is a special day for Ferrari and all its fans, as it is Michael Schumacher's birthday," it said. "At the moment, he is tackling the most important fight of his life and therefore we want to send him very special wishes."