Seriously injured Formula One racing legend Michael Schumacher's recovery is “uncertain,” and the cost of his treatment has ballooned to over $15 million, according to a report in the U.K.'s Express newspaper, which cited insiders.

Schumacher is being cared for in his home in Switzerland, after being released from a French hospital in Sept. 2014. A 15-person medial team cares for him there, according to the paper, but the insider said: “Progress is painfully slow. … There is no miracle on the horizon.”

Schumacher's family have maintained a news blackout on his medical condition since he was released from hospital. However Phillipe Streiff, a friend who visited the ailing star in Nov. 2014, said that he was paralyzed, confined to a wheelchair, and suffering from memory and speech problems. Schumacher's management denied Streiff's claims.

A January report from Italy's Autosprint magazine claimed that Schumacher sometimes cries when he hears the voices of his family but that he spent much of this time “staring into the void,” and was unable to communicate.

Other recent reports have suggested that the driver, who won a record seven Formula One world driver's titles during his career, can convey emotions through his eyes, and is responsive to external stimuli.

Schumacher sustained a traumatic brain injury in Dec. 2013, after hitting his head on a rock while skiing off-piste in the French resort of Meribel. He was in a medically induced coma for nine months after he sustained the injury.