Eddie Hearn questions legitimacy of Deontay Wilder's offer to face Anthony Joshua

Anthony Joshua and Eddie Hearn are eyeing 2018 bouts with Wilder and Parker. Richard Heathcote/Getty Images

Anthony Joshua's promoter Eddie Hearn has expressed caution over an offer of 50 million US dollars from rival champion Deontay Wilder for a world heavyweight title unification fight.

Wilder, who holds the WBC version of the title, made the unusual move of emailing Joshua directly to insist his backers had the money -- worth £35.9million -- for a bout which could take place later this year.

Hearn explained that he still required plenty of assurances before committing to any deal, and stated he remains optimistic about a deal despite the talks that he expected to happen with Wilder's representatives in New York on Thursday being called off.

He told Sky Sports News: "We were supposed to meet today with [Wilder's promoter] Shelly Finkel and [manager] Al Haymon. They cancelled that meeting, which was disappointing. I've requested a meeting for tomorrow. We'll see if we can get on that one.

"There is no deal -- there's no contract, there's no serious offer. We have to determine if it is a PR move or a genuine offer.

"For a fighter to send another fighter an email telling them they've got this money is very strange, but it is a wonderful PR move.

"I think it's bringing the fight closer. From our side absolutely no doubt this is the fight that Anthony Joshua wants next. I believe Deontay Wilder wants this fight next so that's always a great move."

Joshua added the WBO title to the IBF and WBA belts he already owned when he dispatched Joseph Parker in a gruelling contest in Cardiff last month.

Wilder has reportedly agreed to make the next defence of his WBC crown against fellow American Dominic Breazeale, whom Joshua dispatched with ease in an IBF title defence two years ago.

But Hearn is clearly determined that if a deal between Joshua and Wilder can be done, the unification contest should take place sooner rather than later.

Hearn added: "This is the fight that boxing needs: an undisputed heavyweight championship of the world must be made. Let's forget 'after', let's do it now."