Formula One world champion Michael Schumacher has been admitted to a Paris hospital for "secret treatment."
According to Le Parisien newspaper, the 50-year-old has been in the cardiovascular surgery department since Monday and is expected to stay in the hospital for two days.
Schumacher is in the care of surgeon Professor Philippe Menasché - who specialises in cell therapy for heart failure.
According to news.com, Schumacher hasn't made a public appearance since a skiing accident in the French Alps five years ago that left him paralysed and in a medically-induced coma for several months.
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The Ferrari great was allegedly walking with his son Mick when he felt and cracked his head on a boulder on the Combe de Saulire above Méribel.
Le Parisien reported that Schumacher has been undergoing infusions of stem cells designed to obtain systemic anti-inflammatory action.
In January, his family released a statement saying he was in "the very best of hands" according to news.com.
Schumacher's wife gave a rare update on his health in June, almost six years after the racing champion sustained brain injuries in a horrific skiing accident in the French Alps.
Corinna Schumacher spoke about her husband's condition ahead of the release of a documentary on his life and career, calling him a "fighter" and declaring he "will not give up."
According to the Daily Express former Ferrari boss and close friend of Schumacher Jean Todt is deeply saddened by the circumstance.
"His family is fighting just as much and of course our friendship cannot be the same as it once was," he said.
"Just because there’s no longer the same communication as before. I can only say that his family is taking good care of him and he continues to fight."