Irish mixed martial arts fighter and former UFC champion Conor McGregor has denied allegations of sexually assaulting a woman at an NBA basketball match in Miami, according to multiple news reports.

ESPN and TMZ Sports on Thursday cited letters from the womans lawyer which said McGregor violently assaulted her in a toilet at the Kaseya Center during the Miami Heats game four defeat to Denver in the NBA Finals on June 9.

The 34-year-old former UFC star is alleged to have aggressively kissed his accuser before attempting to force her into sex acts.

A statement from McGregors lawyer Barbara Llanes said: The allegations are false. Mr McGregor will not be intimidated.

Police in Miami, meanwhile, would only confirm that its special victims unit was investigating a report filed on Sunday.

Both the Miami Heat and the NBA said they were aware of the reports and are investigating.

We are aware of the allegations and are conducting a full investigation, the Heat said in a statement. Pending the outcome of the investigation, we will withhold further comment.

In the letters, the womans lawyer, Ariel Mitchell, contends security for both the team and the NBA forced the woman into a toilet where McGregor and his security guard were waiting.

McGregor sat courtside at the game on June 9 and took part in a halftime promotional act in which he punched the Heat mascot several times. Burnie, the mascot, had to go to the emergency room and was sent home with pain medication, USA Today reported.

McGregor, who was booed by many in the crowd at the NBA game, has not fought since injuring his left leg in a loss to Dustin Poirier in July 2021. His last win came in January 2020. (Al Jazeera)

PHOTO:Former UFC champion Conor McGregor promotes a pain-relief spray during a break in Game 4 of the basketball NBA Finals between the Miami Heat and the Denver Nuggets on June 9, 2023, in Miami [File: Lynne Sladky/AP]