Michael Schumacher’s medical files are being offered for sale, his management team has warned.
Manager Sabine Kehm said it was unclear whether the documents were genuine.
However, Sabine Kehm said documents were “clearly stolen” and warned that criminal charges would be pressed if such “confidential files” were bought or published.
Michael Schumacher, 45, was placed in a coma after a skiing accident in December but has now left hospital.
It is not clear what the alleged medical data might contain or relate to.
However, in a statement Sabine Kehm said: “For several days stolen documents and data are being offered for sale. The offerer claims them to be the medical file of Michael Schumacher.
“We cannot judge if these documents are authentic. However, the documents are clearly stolen. The theft has been reported.”
She added: “The contents of any medical files are totally private and confidential and must not be made available to the public.
“We will therefore, in every single case, press for criminal charges and damages against any publication of the content or reference to the medical file.”
Michael Schumacher’s management team announced on June 16 that the F1 champion had left hospital in Grenoble in France and was no longer in a coma.
The seven-time F1 champion has been transferred to Lausanne university hospital in Switzerland.
Michael Schumacher was placed in a medically induced coma after suffering a severe head injury in a skiing accident in the French Alps on December 29.
Medical experts say rehabilitation from this sort of injury could take months or years.