Floyd Mayweather's June 27 exhibition boxing match against Mike Zambidis is in jeopardy — and so are many more of his millions.

Mayweather was sued Thursday in a federal court in New York by promoter CSI Entertainment, which claims the Hall of Fame boxer pocketed $ 4.65 million in advances to fight Mike Tyson and Manny Pacquiao, but then walked away from the deal, according to the 34-page complaint obtained by Uncrowned.

CSI Entertainment is asking the court to grant an injunction stopping Mayweather from facing Zambidis and preventing Mayweather from taking any fight other than against Tyson next with CSI and for him to face Pacquiao — or another opponent of CSI's approval — immediately after Tyson.

The promoters are also seeking monetary damages in an amount to be determined for Mayweather's alleged breach of his exclusive two-fight agreement. In the event the courts do not grant these damages, CSI is seeking restitution of $ 6.65 million, including $ 2.15 million from Mayweather, $ 2 million from Frist Apex Ventures and another $ 2.5 million from Mayweather and Frist.

CSI says that on Aug. 10 of last year, it agreed on a deal for Mayweather to take on Tyson in an exhibition bout for $ 14 million with a $ 2 million advance wired the following day.

On Nov. 6, it allegedly reached an agreement with Mayweather to rematch Pacquiao in a professional fight for $ 50 million guaranteed or $ 35 million guaranteed and 20% of the pay-per-view revenues for the bout. The Pacquiao deal had a caveat that if he wasn't available, Mayweather would face another opponent for $ 25 million guaranteed or $ 20 million and 20% of PPV revenues for the contest. CSI claims it advanced Mayweather and Frist $ 2.5 million on Nov. 6.

After Mayweather completed his medicals on March 1, he was paid another $ 150,000 in cash. CSI says that representatives hand-delivered the money to a female associate of Mayweather's at the Peninsula Hotel in Beverly Hills. The following day, Mayweather promoted the Zambidis exhibition on Instagram, which CSI alleges amounted to a violation of their contract.

CSI argues that it was paying for the exclusive rights for Mayweather's next two fights to be against Tyson and Pacquiao consecutively. The complaint says that clauses in both Mayweather deals to fight Tyson and Pacquiao prevented him from taking any other fight before Tyson or in between Tyson and Pacquiao, and when Mayweather announced his exhibition match with Zambidis, he interfered with those rights and caused CSI "irreparable harm."

An exhibition between Mayweather and Tyson was scheduled for May 30, but an injury to Tyson forced it to be postponed. CSI says that if Tyson was fit to fight by Nov. 30 — which it claimed he would be — then Mayweather was still bound by the contract. Instead, it claims he broke the deal when announcing his exhibition against Zambidis.

The 34-page complaint also claims that while under contract with CSI, Mayweather entered into a separate promotional agreement with Everwonder Studios for a Pacquiao bout that was intended to air on Netflix, once again said to be breaching CSI's exclusive rights.

The lawsuit is the latest legal and financial issue facing Mayweather. In April, the Internal Revenue Service (IRS) filed a $ 7.3 million lien in Las Vegas against the former pound-for-pound king for unpaid taxes dating back to 2018 and 2023. And earlier this week, news broke that Mayweather was facing two felony criminal charges over a bad check. He is also suing Frist for $ 175 million and Showtime for at least $ 340 million.