The family of Michael Schumacher described the Formula One legend as a fighter who "will not give up", as he turned 45 on Friday while lying comatose in a French hospital.

"Following Michael's skiing accident, we would like to thank the people from all around the world who have expressed their sympathy and sent their best wishes for his recovery," the Schumacher family said in a statement posted on the German racing great's website.

"We all know he is a fighter who will not give up" they added, in the message coinciding with his birthday.