BERLIN (AFP) - Formula One legend Michael Schumacher, who is still lying in a coma in a French hospital, has contracted a lung infection, the German newspaper Bild reported on Wednesday.

The effects on the fragile state of health of the 45-year-old were unknown, it said, without citing sources.

Schumacher's spokesman, Sabine Kehm, told the newspaper: "We are not commenting on speculation."

He has been in a coma since his Dec 29 ski accident, when he badly injured his head, causing serious swelling of the brain.

The doctors treating him in the hospital in the French city of Grenoble two weeks ago said they were trying to coax him out of the coma by reducing his sedation.

Kehm said the process could take some time.

With little information being given to media, the hospital has been left to fend off rumours. Last Thursday, it had to deny speculation flaring on social networks that Schumacher, who won 91 Grands Prix, had died.