Mark Cavendish has revealed that he is "not optimistic" about his hopes of continuing at the Tour de France following a heavy crash that led to world champion Peter Sagan being disqualified.

Sagan was initially docked 30 seconds after appearing to nudge Dimension Data sprinter Cavendish into the barriers during stage four on Tuesday, just 200 metres or so from the finishing line in Vittel.

The collision caused a big pile-up and, following a review of the incident by race officials, Sagan's hopes of winning the event for a sixth time have been cut short as he has been thrown off the Tour.

Philippe Marien, the president of the race commission, said: "We've decided to disqualify Peter Sagan from the Tour de France 2017 as he endangered some of his colleagues seriously in the final metres of the sprint which happened in Vittel."

Cavendish's future in the race is now in major doubt, meanwhile, as he was taken to hospital with his right arm in a sling.

"Injury-wise I'm going to go and get it checked out," he said. "I definitely need stitches in this finger, it's bleeding a lot. And the shoulder, there's something to do with that previous shoulder that I did in Harrogate - it's just sat backwards.

"I don't know if I've snapped the fake ligament or what - I'm going to go and get it looked at. I'm not a doctor, I don't know what, but I'm not optimistic anyway."

Frenchman Arnaud Demare won the race, with Cavendish managing to cross the line several minutes later following some medical treatment.