Michael Schumacher's management has described reports suggesting that he is being "woken up" from a medically-induced coma as speculation.
However, they did not deny a report in a French sports daily that the seven-time Formula One world champion had "reacted positively" to the process.
It is a month since Schumacher was involved in a skiing accident at the French resort of Meribel that resulted in him requiring surgery to remove blood clots from his brain.
The 45-year-old has been in an artificially-induced coma at the University of Grenoble hospital.
Given the length of time Schumacher has remained in such a condition, some experts have questioned if he could ever make a full recovery.