Newly-crowned WBA heavyweight champion David Haye could be heading for a massive showdown fight with one of the Klitschko brothers at Wembley Stadium.

Adam Booth, Haye's trainer, revealed that discussions with Wembley Stadium are already under way following his victory over giant Russian Nikolai Valuev in Germany on Saturday night, and the fight could take place next summer.

"Wembley have already been on to me," said Booth. "Haye against a Klitschko, Wladimir or Vitali, would be one of the biggest fights in heavyweight history."

The sheer scale of the gate receipts from a sell-out 100,000 Wembley crowd, combined with his percentage of the pay-per-view TV subscriptions, could earn the London-born champion an estimated £20million.

But Haye, 29, still celebrating his 12-round majority points success over 7ft 2in Valuev, has to defend his title with a mandatory fight against challenger John Ruiz before then.

"Ruiz is the mandatory challenger for the WBA title so if I don't fight him they'll take the title from me, and I don't fancy giving it up after winning it," said Haye. "I feel I can knock out John Ruiz."

He added: "Ruiz is a good fighter, very underrated. But I will upset him pretty badly.

"He's not the most entertaining of former champions but he's won championships on several occasions, and you don't do that through being a bad fighter. I don't feel I'd struggle with him in any way, though.

"I said I want to be unified champion and the Klitschkos are definitely in my sights. I am not fussed which one it is. Whichever one is available, we'll sit round a table and make it happen. Fingers crossed they retain their titles and we can have a huge, huge, unification fight."

Wladimir, at 33 the younger of the brothers, holds the IBF and WBO versions of the heavyweight championship. But it is 38-year-old Vitali, the WBC champion and generally regarded as the world's best heavyweight, who has already made it clear he would be willing to face Haye.