Michael Schumacher's former Mercedes boss has called on the Formula One driver's family to provide more information about his condition.
French newspaper Le Parisien claimed on Monday that Schumacher, who has not been seen in public for almost six years following his skiing accident, has been admitted to a Paris hospital for "secret treatment".
Schumacher's management have declined to comment on the latest report.
Schumacher has been recovering at the family home in Lausanne, Switzerland after he sustained serious head injuries in December 2013. There have been few updates about his well-being.
To coincide with his 50th birthday last January, the family issued a rare statement, saying they "are doing everything humanely possible" to help the seven-time world champion, and "that he is in the very best of hands".
The wall of secrecy, enforced at the request of Schumacher's wife Corinna, was established to protect one of the biggest names in modern sporting times.
But, writing in his forthcoming book, Nick Fry, who worked alongside Schumacher for three years at Mercedes, believes the sporadic offerings about a driver who won a record seven world championships, 91 grands prix, and commanded a following of millions around the world, are not enough.
"Corinna and the family have kept a very tight control on information about his treatment which, I think, is a pity," Fry wrote in his book, Survive. Drive. Win., seen by the PA News agency.
"There are millions of people out there who have a genuine affection for Michael, and that's not just his fans in Germany or fans of Mercedes Benz.
"Because of what he achieved, people would like to know about his condition; they are inquisitive and they genuinely feel for him.
"I do think that reporting on how he is, regardless of whether it is good or bad news – and possibly it is bad news – is important because people can empathise with him."
Fry was chief executive for Mercedes during Schumacher's largely unsuccessful second spell in Formula One. He was replaced at Mercedes by Toto Wolff in 2013.
"From what I understand, Michael's family have been able to give him the best treatment that money can buy in a specially constructed facility at the family home in Switzerland where he is looked after by a dedicated team around the clock," Fry continued.
"I am sure that techniques and therapies have been developed and tried there over the last few years that may well help others.
"It would be helpful for his family to share how they have dealt with this challenge because there are lots of people in a similar situation who would probably find it beneficial to have that first-hand experiences."
:: Survive. Drive. Win. The Inside Story of Brawn GP and Jenson Button's Incredible F1 Championship Win is by Nick Fry with Ed Gorman, published by Atlantic Books on October 3.