A mystery third heavyweight has joined Oleksandr Usyk and Derek Chisora in the running to face Daniel Dubois outdoors in London this July.

The IBF heavyweight champion has not boxed since he poleaxed Anthony Joshua in the fifth round of their Wembley Stadium clash on September 21.

He was forced to withdraw from a scheduled defence against Joseph Parker in Riyadh on February 22 due to illness but it has now been confirmed that he will return to the ring in July.

The two options for the fight had appeared to be either an undisputed showdown with Ring Magazine champion Usyk, who would also put his WBA, WBO and WC belts on the line, or Chisora.

The 41-year-old Finchley man has been installed as mandatory challenger by the IBF and Dubois would therefore have to face him, or risk losing his belt, unless he could agree the unification with Usyk instead.

But now Dubois’ promoter Frank Warren has revealed to The Ring that negotiations are actually continuing with three different heavyweights for the fight, which is expected to land at either Wembley or Tottenham Hotspur Stadium.

“Daniel will definitely fight in July but we’re just working out who it’s going to be,” Warren said.

When asked to confirm if it was a two-horse race between Usyk and Chisora, he then said: “It’s actually out of three, but I’m not going to go there and tell you who.

“I hope it will be confirmed in the next week or so.”

A contracted rematch with Joshua had been previously mooted and the two-time world heavyweight champion is still No.5 with the IBF despite his defeat to Dubois. Heavyweight prodigy Moses Itauma is currently ranked at No.9 but he is expected to box in Glasgow on May 24.

But while Warren remained tight-lipped on the identity of the third man, he did rule out a sensational return for 49-year-old Wladimir Klitschko, who held the IBF title for nine years, in this particular fight.

Parker, who hasn't fought in a world title contest for over seven years, could also be an option, but the New Zealander isn't ranked in the top 15 with the IBF.