The German suffered serious head injuries in a skiing accident in 2013 and has not been seen in public since.

The former Ferrari driver is being treated at his home in Switzerland, but little is known about his recovery.

"You can be sure that he is in the very best of hands," his family said.

"We are doing everything humanly possible to help him.

"Please understand if we are following Michael's wishes and keeping such a sensitive subject as health, as it has always been, in privacy."

Formula 1 managing director Ross Brawn, who was Schumacher's team principal at Ferrari, said: "I am constantly in touch with [Schumacher's wife] Corinna and I totally agree with their decision.

"Michael has always been a very private person and that's been a guiding principle in his career, his life. His family always agreed with that choice."

On Thursday, Schumacher's family will release the Official Michael Schumacher App, which will be a "virtual museum" of the driver's achievements.

Schumacher's career in numbers

• 7 - a record seven world championships - two with Benetton in 1994 and 1995, and five in a row for Ferrari from 2000 to 2004.
• 91 - race wins, from 306 starts - he remains 18 clear of second-placed Lewis Hamilton on the all-time list.
• 68 - pole positions, a record beaten by Hamilton in 2017.
• 15 - consecutive seasons with a grand prix win, from 1992 to 2006. It is a record - three clear of Hamilton.
• 8 - wins at the French Grand Prix, the most by any driver at a single race. His seven wins in Canada and San Marino are also unmatched by any other driver.
• 17 - podium finishes in 17 races in the 2002 season.
• 43 - age when he drove in his final grand prix, in Brazil in 2012. He originally retired in 2006 but returned three years later.