Floyd Mayweather was involved in a chaotic brawl on Thursday during the build-up to next month's fight with Internet star Logan Paul as tempers boiled over at a press conference in Miami.

The undefeated 44-year-old former welterweight world champion reacted angrily at the Hard Rock Stadium after Paul's brother, Jake, grabbed his cap during a TV interview.

Mayweather chased down the Paul brothers and punches appeared to be thrown in a melee involving a scrum of security staff. Mayweather unleashed an expletive-laden tirade during the incident.

Insults had already been traded in an earlier confrontation, with Logan Paul taunting Mayweather by referencing his 2011 domestic violence case. Mayweather served two months of a three-month sentence after attacking an ex-girlfriend. Mayweather, meanwhile, claimed he would fight - and beat - both Paul brothers on the same night before the event erupted into violence.

Logan Paul had to be pulled away from the melee by his entourage while Mayweather continued to vent his fury before he too was hustled away.

Before the brawl, Logan Paul told AFP he firmly believed he could do what no boxer had ever done before and beat Mayweather.

"After this fight I don't want anyone to tell me something is impossible," Paul said. "I am representing the guy who was counted out, the guy who believed in himself so much that his unrelenting belief in himself propelled him to success. That's me. I don't just think I can beat him. I know I can beat him."

Mayweather meanwhile accused the Paul brothers of failing to show him respect. "You can't keep crossing the line, keep touching me, taking my hat off, touching my shoes," Mayweather told AFP following the skirmish.

"There is a thing called respect and a thing called disrespect. I am not going to tolerate any disrespect. I know how to sell a fight but you cannot cross the line. They can say certain things about me, I can say things about them. But what I won't do is push or touch anyone."

The fight, scheduled for June 6, will be Mayweather's first appearance since he appeared in an exhibition contest in Japan in 2018. Thursday's event gave no further information about specifics of next month's fight such as number of rounds or what size gloves would be used.

Paul, 26, first ventured into white-collar boxing in a bout with British YouTuber KSI in 2018 that reportedly generated 1.3 million pay per view buys worldwide, before a rematch in 2019 in Los Angeles. Mayweather, meanwhile, has not fought in an officially sanctioned boxing bout since beating mixed martial arts star Conor McGregor by technical knockout in a money-spinning 2017 superfight in Las Vegas.

Mayweather (50-0, 27 KOs) came out of retirement for that fight after hanging up his gloves two years earlier following an unbeaten career spanning three decades.