US BMX ace Connor Fields ‘awake and awaiting further evaluation’ after terrifying crash at Olympic race in Tokyo (VIDEO)

American BMX star Connor Fields is 'awake' and recovering in hospital after he appeared to be seriously injured following a heavy crash at the Olympic men's BMX semi-final race early on Friday.

Fields, 28, came off his bike at the first 180 corner in the high-stakes race in the Japanese capital and appeared to land heavily and collide with at least one other rider. 

The American BMX icon was close to the front of the pack when he appeared to collide with another bike, causing the accident when threw him off his bike at high speed.

He was treated on the track for several moments during which time his neck was stabilized with a brace before he was rushed to an ambulance on a stretcher and taken to a nearby medical facility. 

A spokesperson for the US Olympic team later confirmed that Fields was "awake" and that he was awaiting further medical examination, but no further information was offered to the media related to extend of his injuries.

The Texan is one of the premiere BMX stars in the world and is the reigning Olympic champion, having won gold at the same event in Rio in 2016 to add the gold medal he also won at the Pan American Games a decade ago. 

Prior to the accident, Fields had already done enough to qualify for the Olympic final but will now almost certainly miss the event due to his injuries.

"We can confirm that Connor Fields is awake and awaiting further medical evaluation," a US team official detailed to Reuters.

"We will share additional updates as they become available."

The start of the race had been delayed by 45 minutes due to heavy rain which had been blamed for several crashes earlier in the competition but it had cleared by the time Fields was due to compete - with Dutch rider Merel Smulders indicating that she didn't expect that rain was the cause of the crashes.

"I don't think that the track or the weather had anything to do with the crashes," she said. "You know, it's the semi-finals of the Olympics and everyone rides with emotion and they take more risks than normal.

"I feel like there were a lot more crashes in Rio. But there were some bad crashes today and no one wants to see that."

Several fans of the sport have also sent well-wishes to Fields, with some indicating that high-speed crashes such as this are just an unfortunate part of BMX racing.

"There's a wreck/tangle-up on almost every single BMX run... I do hope they're alright, but it makes it extremely interesting," wrote one, while others were simply hoping that Fields emerges from the horror smash largely unscathed.

"So horrible to see this. Please let him be ok," said another fan, while a third agreed that the accident was "terrifying to watch".