"Michael's condition is still considered as stable," Sabine Kehm said of Schumacher, who has been in a medically-induced coma since his life-threatening off-piste fall in the French Alps.
"Unfortunately I have to repeat that any information regarding Michael's health not coming from the doctors treating him or from his management must be
treated as pure speculation," she said.
"I also repeat that Michael's family is very happy and confident with the work of the team of doctors treating Michael, and they trust them completely."
Investigators probing the crash have ruled out faulty skis, inadequate signage and excessive speed as reasons for the accident, in which he slammed his head against a rock.
Schumacher appears to have skied on a partially covered rock, lost his balance and fallen on another rock further down, according to the prosecutor in charge of the probe.
The impact was so strong it split his helmet in two.
The accident in the posh French resort of Meribel has shocked Schumacher's legions of fans and devastated his wife Corinna and two teenage children.
Schumacher dominated Formula One before retiring in 2012, winning more titles than any other driver and enjoying 91 Grand Prix victories between 1994