Tommy Fury has been denied access to the US ahead of his planned fight with Jake Paul

Fury - who is the half-brother of heavyweight champion Tyson Fury - said: "I have no clue why they would not allow me to travel today and neither does any of my team or my lawyer. I'm trying to resolve it. I'm in the middle training, guys. It's a massive shock to me and my team."

Fury has been in training for the fight over recent weeks, but it's now unclear whether it'll happen at all.

He added: "As soon as I entered the airport I got pulled to one side and I was told by a Homeland Security officer that was there ... that my ESTA [travel authorisation] had been denied and I wasn't able to travel to the USA for a reason that I apparently know."

His opponent has already taken to social media, suggesting that their much-hyped fight could still take place.

The YouTuber-turned-boxer said on Twitter: "Tommy, no matter how hard you try to get out of this fight, I'm going to do everything in my power to not let you weasel your way out.

"My team and my partners have made it clear the steps you need to take to solve your latest excuse."

Meanwhile, Most Valuable Promotions - who organised the fight - have been surprised by the situation.

The company said in a statement: "Despite many assurances by Tommy Fury and his team that he was able to come to the U.S., and knowing that Tommy was in California just last month, we were surprised to learn that he had an issue at Heathrow airport on Monday."