English challenger Gary Corcoran has claimed Australian World Boxing Organisation welterweight champion Jeff Horn is a "dirty" fighter ahead of their title bout in Brisbane on Wednesday.
In an extraordinary media conference Monday, Corcoran's camp provided a laptop presentation to indicate that Horn led with his head and left his head in the clinches.
It is Horn's first title defence since he upset Philippine boxing hero Manny Pacquiao, the winner of eight world championships in different weight divisions, in Brisbane last July to win the belt.
"Let me start by saying I respect Jeff as a fighter ... they don't give away world title belts for nothing," Corcoran's co-trainer Frank Greaves said.
"(But) let's get one thing straight. He is dirty. There is absolutely no question that he's dirty.
"He's leading in with his head, he leaves his head in there all the time. I just want to draw attention to that fact."
Greaves aired a collection of video highlights which he claimed proved his point.
The trainer also taunted Horn by pulling out a baseball cap with a boxing glove taped to it before a bout of bickering broke out between the two teams.
Horn's trainer Glenn Rushton hit back at the Corcoran camp's claims.
"Jeff doesn't headbutt," Rushton said.
"What you're not factoring in is all the unknowns -- someone moves their head this way just as he moves his head.
"You've got two explosive fighters in Manny Pacquiao and Jeff Horn, both very evasive and fast moving. Sometimes they both zig when one should have zagged -- boom, there's a head clash."
Horn also fired back at the suggestion he was "dirty".
"Maybe I can change that hat to having gloves on the side of my head to protect my ears from the biting," he said.
Rushton added that he will only be satisfied with a Horn knockout victory to send a warning to the rest of the welterweight division overseas.
He also insisted he wants Horn to beat those main rivals -- Americans Terence Crawford, Errol Spence and Keith Thurman -- before going up a weight division.
British boxer Amir Khan is another who has designs on Horn's world title belt and is expected to be ringside on Wednesday with a potential fight between the two next year.