If not for legendary Boston gangster James "Whitey" Bulger, the UFC as we know it today may not exist.

Bulger -- who is the subject of the new film "Black Mass," set to release in theaters on Sept. 18 starring Johnny Depp in the lead role -- was a mainstay in the organized crime scene around Boston, and his gang actually had a run-in with UFC president Dana White long before he was a successful mixed martial arts promoter.

White has previously told the story about Boston mobsters forcing him to flee town and move to Las Vegas after being told he had to begin paying them to operate in their neighborhood or else.

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On Wednesday while appearing on "The Herd" with Colin Cowherd on FS1, White said it was actually Bulger's top man who came to see him on that fateful day that eventually led to him moving to Las Vegas, where he reconnected with old friends Frank and Lorenzo Fertitta.

"My partner and I, Peter (Welch), we ran a 'get kids off the street' program back there and we used to teach boxing classes, however we could make money, we made money. So one day I was teaching a class in one of the big clubs in South Boston and these two guys walked into the class and said, 'Hey, we need to talk to you.' At first I'm thinking, 'Does this guy own the club?' and when he asked me, 'Do you know who I am?' that was when I realized what was going on," White said.

"He basically said, 'You owe us money'. It was like $2,500, which was like $25,000 to me back then, and said, 'You owe us money.' It was actually a guy named Kevin Weeks, who if you saw the trial he's Whitey's right-hand man. I'm sure he's very prominent in the movie, but yeah basically said I owed him some money, and I didn't pay him. This went on for a while and one day I was at my place and I got a call and they said, 'You owe us the money tomorrow by 1 o'clock'. I literally hung up the phone, picked up the phone and called Delta and bought a ticket to Vegas."

In the upcoming film, "Breaking Bad" star Jesse Plemons actually plays Weeks in the movie opposite Depp as Bulger.

White says his lone run-in with The Winter Hill Gang was enough for him to get out of Boston, move to Las Vegas and never look back.

"I literally left everything there. I packed a bag and left all my stuff in Boston," White said.

A few years later, White teamed up with the Fertitta brothers to buy the UFC for a total price of $2 million and the rest is history.

Bulger is serving out two life sentences after being convicted in 2013 on charges including racketeering and murder.