Khamzat Chimaev has been labelled "a fake gangster" by Jake Shields after trying to start a fight with Paulo Costa.

The rising UFC star will return to the Octagon in the main event of UFC 279, which will take place at the T-Mobile Arena in Las Vegas on September 10.

Chimaev will be welcomed back to the cage by fellow fan favourite Nate Diaz, who has one fight left on his contract.

The Swedish MMA fighter recently moved to 11-0 in his professional mixed martial arts career by edging past Gilbert Burns in their thrilling back-and-forth battle in April.

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And now footage has emerged of him confronting Costa in a recent altercation at the UFC Performance Institute in Las Vegas.

The pair clashed furiously after randomly bumping into each other at the state-of-the-art training facility before being separated by team-mates.

But Shields believes Chimaev is continuing to con the public by trying to act all tough in front of the cameras.

Khamzat Chimaev takes on Nate Diaz on Saturday

He told MMA Junkie: “I was there this morning working out with Paulo Costa, going over some techniques and just drilling, and all of a sudden Khamzat starts yelling at us and cussing Paulo like, ‘Well, you want to fight?'.

“We look over, and it’s him and like 10 dudes.

“So Paulo jumps up and starts talking s***.

"I run over to back up Paulo because I don’t know if they’re trying to jump him, right?

"There were a couple of guys, so I wasn’t sure if they were going to jump him.

"There were a couple of guys that we didn’t recognize.

“So we run over and start talking sh*t and Khamzat keeps going, ‘Let’s fight now, let’s fight now,’ but as he’s saying that he’s walking down the stairs.

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"It seemed like it was kind of more of an act for the cameras than anything.

"I guess someone said afterward that he was scoping us out for 10 minutes.

"If he wanted to fight Paulo, he would’ve run in there and started swinging on him, not stood outside the cage and say, ‘Let’s fight right now. Let’s fight right now.’

“It seemed kind of a weak thing. I guess that’s why he was upset because Paulo called him a fake gangster, and that was a perfect example of him being a fake gangster.”