Machine Gun Kelly and Conor McGregor were involved in an altercation on the MTV Video Music Awards red carpet on Sunday night.
Pictures and videos taken from the start of the red carpet outside the Barclays Center in Brooklyn show the UFC fighter and My Bloody Valentine singer being restrained and pulled apart by security after the scuffle broke out.
It's not clear what caused the fight, but a source told People that McGregor asked to take a photo with Kelly, but the rapper's team turned down his request, while an insider told New York Post's Page Six that McGregor threw his drink over Kelly.
Despite the video evidence, a representative for the Irish mixed martial artist insisted that a fight didn't occur, adding, "Conor only fights fighters." His rep told People that McGregor didn't ask for a photo.
McGregor was adamant "absolutely nothing" happened when asked by Entertainment Tonight later on the red carpet.
"He showed up, and I don't know. I don't know the guy," he said. "Nothing happened with me, I only fight real fighters, people that actually fight, you know what I mean. I certainly don't fight little vanilla boy rappers. I don't even know the guy. I don't know anything about him, except that he's with Megan Fox."
Kelly and his girlfriend, actress Megan Fox, were asked about the scuffle when they spoke to Variety and the rapper made an exasperated noise before slapping the microphone and walking away. As they left, Megan explained, "We're not allowed to say."
The rapper was due to perform his new song Papercuts with Travis Barker midway through the awards show, but despite the set being prepared on the stage, there was a last-minute change of plan and it was pushed to the end of the ceremony. It is currently unclear why it was delayed.