Schumacher remains "critical but stable" in hospital in Grenoble after a skiing accident. A statement from Sabine Kehm said reports not from managers or doctors "must be treated as pure speculation".
The statement also rejected reports a camera fixed to Schumacher's ski helmet had not been handed over voluntarily.
The German champion, who retired in 2012, is in a medically induced coma after suffering head injuries during a fall in the resort of Meribel last Sunday. His helmet cracked on impact when he hit a rock while skiing off-piste.