David Haye throws punch at opponent Tony Bellew in press conference
Former WBA heavyweight champion David Haye threw a punch at Tony Bellew when they met at a news conference on Wednesday to promote next year's fight.
The pair, who meet at London's O2 Arena on 4 March, went head-to-head before Haye reacted to a shove from Bellew.
WBC cruiserweight champion Bellew, 34, had previously taunted 36-year-old Haye after retaining his title by knocking out BJ Flores in October.
"He's unbelievable, the biggest diva boxing has ever seen," said Bellew.
Haye returned to the ring in January after a three-and-a-half-year absence with a knockout win over Mark de Mori, before beating Arnold Gjergjaj in May.
The Londoner has been mentioned as potential opponent for IBF heavyweight champion Anthony Joshua.
"You could be fighting for the heavyweight championship of the world, but you're fighting me," added Bellew, who will step up to heavyweight for the first time. "And you know why? For the money. You're skint."
Liverpudlian Bellew also had time away from the ring - to play a supporting role in the Rocky spin-off Creed - before winning the world title with a third-round knockout of Ilunga Makabu at Goodison Park in May.
He added: "You were giving tickets away outside [at your last two fights]. You're struggling, and you don't want a real fight."