Schumacher, who spent six months in an induced coma following the crash, has been receiving specialist medical care at home on the shores of Lake Geneva since September 2014.
About two weeks ago, Luca di Montezemolo, the former Ferrari president, said the 47-year-old's health was "not good".
"I have news and unfortunately it is not good," Mr Di Montezemolo told reporters, refusing to elaborate. "Life is strange. He was a fantastic driver and only had one accident with Ferrari in 1999," he said, referring to an accident during the British Grand Prix in which Schumacher broke his leg.
Ever since the skiing accident happened, there has been much speculation about Schumacher's condition, with many reports being rebutted by Ms Kehm.
She accused Bunte magazine of raising "false hopes" shortly before Christmas when it claimed the Formula One star was walking again.
According to earlier reports he is paralysed and confined to a wheelchair, has memory problems and cannot speak. Nearly two years after the accident, FIA President and close friend Jean Todt said Schumacher was "still fighting" in his recovery.
-The Telegraph