Peter Sagan and stage eight winner Jasper Stuyven out of Vuelta

Sagan, 25, was knocked off his bike inside the final 10 kilometres of stage eight in the latest controversial incident involving the motorised support vehicles of major races this season.

The Slovakian sprinter - who was wearing the green jersey at the time and was tipped to take a second victory in Murcia - was forced to abandon the race because of his injuries, which included first and second degree burns on the left side of his body and a contusion on his left forearm.

Although the motorbike driver has been ejected from the Vuelta by race organisers, Sagan himself was fined 300 Swiss francs for his heated reaction to the incident.

"He lost a lot of skin so we decided to take him out of the race," said Tinkoff-Saxo sporting director Tristan Hoffman. "He's going home to prepare for his other objectives of the end of the season.

"I went to see the footage of the crash with the organizers and it's very difficult to say what happened except that the motorbike was probably going too fast.

"It was the right decision to take the motorbike out of the race because we need to give a strong signal. There are more and more motorbikes around the race and safety must come first.

"I find it a bit unfair that Peter should be fined because he didn't hit anybody. It was just the adrenalin you get after a crash."

Tinkoff-Saxo are said to be considering legal action following the incident - which not only deprived Sagan of a chance to add to his stage victory tally, but has now ruled him out of the race altogether.

"Unfortunately, it isn't the first time such an incident happens," Sagan said in a team press release after the accident.

"Even if motorbikes are forced to go through a group of riders, they should do it very carefully and not recklessly. In my opinion, motorbike drivers don't take the safety of the riders in consideration seriously.

"Fortunately, my injuries aren't very serious but can you imagine what would have happened if he had ran over me?"

Sagan eventually finished the stage more than five minutes down on Belgian stage winner, Jasper Stuyven of Trek Factory Racing.

But it emerged after the stage that 23-year-old Stuyven had fractured the scaphoid bone in his left wrist when coming down in the crash that ended the race for American Tejay Van Garderen (BMC), Frenchman Nacer Bouhanni (Cofidis) and Ireland's Dan Martin (Cannondale-Garmin) - plus has seen another Belgian, Kris Boeckmans of Lotto-Soudal, put in an induced coma after severe facial injuries.

Despite his breakthrough win, Stuyven was withdrawn from the race by his Trek team ahead of Sunday's stage nine on the Costa Blanca. He will undergo surgery on his hand but should be back on his bike in a couple of weeks.

“Like I said after the finish, I felt my wrist and it was getting more and more painful, so I asked to go to the hospital to make the check," Stuyven said in a statement from his Trek Factory Racing Team.

"I was already scared that it could be the scaphoid because I know from friends who are cyclists what the pain feels like and where it’s located. And, unfortunately, the X-rays confirmed that it is broken and that my Vuelta finishes today.

“At first I was of course really disappointed, but then I realized that I really have to enjoy this moment, because now is the time to enjoy my first professional win. For what’s next, I will see when I get home and have the surgery."