A Manhattan federal judge denied a prizefighter known as “Mini Mike Tyson” bail on Friday after prosecutors said his workout regimen includes beating people up on behalf of a reputed Russian mob boss.

Judge Katherine Forrest ordered middleweight boxer Avtandil Khurtsidze, 37, to jail after the feds told her they have video showing him acting as “muscle” for reputed mob boss Razhden Shulaya in Brooklyn.

The World Boxing Organization fighter is among 33 people indicted for their alleged involvement with a Russian crime syndicate.

Arguing in court Friday, the feds said the boxer is seen in one video punching a man accused of stealing money from a poker game.

He struck the man with “extreme force,” allowing Shulaya, 40, to step in and slap the man around, said prosecutor Andrew Adams.

The boxer had been slated to fight Billy Joe Saunders for the WBO middleweight title in London on July 8, but the bout was canceled Thursday, a day after his indictment on racketeering, fraud and other charges.

Khurtsidze’s lawyer, Guy Oksenhendler, denied his client was an enforcer, saying recordings of him hitting or threatening people were taken out of context.

“He’s a peaceful man. He’s a warrior in the ring,” Oksenhendler said.

The lawyer also said Khurtsidze was around reputed mobsters only because they sought him out.

“People tend to gravitate toward him because of his renown as a fighter,” he told the judge.