Representatives of the two Britons are in dialogue, but neither side is negotiating monetary splits or wider demands at this stage.

Joshua's promoter Eddie Hearn said they are "talking" about how a bout for all the heavyweight belts could happen.

One source close to the discussions told BBC Sport they now believe the fight "will happen" and confirmed talks were under way.

Authorities in Saudi Arabia - the country that staged Joshua's rematch victory over Andy Ruiz jnr last December - are keen to secure the bout.

After working closely with Hearn to host Joshua-Ruiz, a member of the country's royal family sat next to promoter Frank Warren in Las Vegas to watch Fury win the WBC belt from Deontay Wilder in February.

Wilder has a contract to face Fury again, while Joshua - holder of the IBF, WBA and WBO belts - is slated to face Bulgaria's Kubrat Pulev when sport resumes after the coronavirus shutdown.

At this stage, establishing how much money could be generated by a Joshua-Fury bout is seen as key as it would allow clarity on what could be offered to Wilder and Pulev in order for them to break the contracts they have in place.

The 'step aside' money on offer for both men would be several million dollars and there is a feeling privately that Wilder - who has just had surgery - would take it.

"Negotiations aren't under way," Joshua's promoter Hearn told Sky Sports on Thursday.

"What I can tell you is we are talking. We are all on the same page. You will get this fight, it's just a case of where and when.

"There is the major hurdle that we are both under contract for other fights. Everything is solvable with money."