UFC president Dana White has taken a swipe at promoter Eddie Hearn and called him "very oversensitive" with respect to the circulating reports that White had made an offer of $500 million to promote WBO, IBF, WBA, IBO heavyweight champion Anthony Joshua.

White has been exploring the possibility of starting his own boxing promotion, called Zuffa Boxing, and he's been holding conversations with numerous names like Joshua, Mikey Garcia and others - to sign them up to new venture.

In a recent interview, White denied that he ever made an offer of $500 million to Joshua, but he does admit to speaking with the boxer.

Hearn has promoted Joshua since the Olympic gold medal winner turned pro in 2013 - and the fighter's promotional contract with Matchroom has come to an end.

White explained that he had spoken with Joshua over the phone, but two of them never met or spoke further on working together.

"It's not true [that I offered Joshua $500 million]," White told The MMA Roasted.

"Me and Joshua spoke on the phone. We never got together. His contract was coming up and I said, 'Listen, I would like to talk to you guys.' He made it very clear to me that he wasn't going to leave Eddie and that he wanted to stay with Eddie.

"I said: 'Yeah, I'm not looking for you to leave Eddie, we can all work together, I think we can do a lot for you here in the United States.' Eddie Hearn hasn't been in the business that long. I think Eddie Hearn was very oversensitive over the thought that Anthony Joshua and I would even talk and was almost insulted by it."

Joshua is slated to return on a date in September, and WBA mandatory challenger Alexander Povetkin of Russia is currently the frontrunner to become the opponent in the corner.