After he crashed in today's Tour de France stage, Vincenzo Nibali has been accused of mechanical doping. Astana threaten to take legal action.

Nibali crashed on the descent and as images show how his wheel keeps turning, some have accused him of mechnical doping. The same happened for Ryder Hesjedal in the Vuelta two years ago.

Astana have reacted quickly by issuing the following statement:

"In relation with the suspects about the Vincenzo Nibali's rear wheel rotation during his fall in today's stage at Tour de France, the Astana Pro Team informs that during the three weeks of racing we have been subjected to the UCI checks daily, always resulting perfectly in order.

"The Astana Pro Team and Vincenzo Nibali reserve the right to take legal action in case someone will threaten the image of the Team or of the athlete.

"In a separate note, the Astana Pro Team wish to thank its partner Corima Wheels and Ceramic Speed Bearings to have provided such great products that apparently it takes a much longer time to stop in the particular case of this crash."