'That's the maximum for him': Doctor's worrying new claim about Michael Schumacher

A new documentary aired on French TV has shone more light on Michael Schumacher's current condition.

The legend's health has been at the centre of mounting speculation of late as son Mick's elevation to F1 is being strongly considered.

Yet a leading doctor's worrying assessment in the documentary is a bleak wake up call to fans who were hoping the Ferrari great would some day return to full health.

Swiss neurologist Erich Riederer said Schumacher is in a "vegetative state" and not responding to his family.

"I think he's in a vegetative state, which means he's awake but not responding," he told TMC.

"He is breathing, his heart is beating, he can probably sit up and take baby steps with help, but no more.

"I think that's the maximum for him. Is there any chance of seeing him like he was before his accident? I really don't think so."

Despite wearing a helmet, the German was placed in a medically-induced coma after he suffered a near-fatal brain injury in 2013 skiing in the French Alps.

Schumacher's health has been shrouded in secrecy. What is known Schumacher had regained consciousness by June 2014 and left Grenoble Hospital for further treatment in Lausanne, Switzerland.

Later that year he left the Swiss hospital to continue his recovery at home and it was reported Schumacher was "paralysed and in a wheelchair" and he "cannot speak and has memory problems".

Riederer, who works at a private clinic in Zurich, speculates that Schumacher's treatment was delayed at an early stage and he should have had surgery as soon as possible.

The doctor criticized doctors at Grenoble University Hospital.

"Neurosurgeons always say 'time is brain', which means you have to act now. In my opinion, they waited too long for the brain to shut down.

"If you let too much time pass, you will destroy the brain substances."