The lawsuit also requests an injunction that would prevent Mayweather from participating in his June 27 exhibition bout in Athens, Greece, until the dispute is resolved.
The proposed Pacquiao and Tyson matchups were among the highest-profile exhibition concepts discussed in recent years. Neither fight ultimately took place, leading CSI to allege that it is owed reimbursement for money advanced under the agreements.
Mayweather, 49, has remained active on the exhibition circuit since retiring from professional boxing with a perfect 50-0 record. While he has not competed in an official professional bout since stopping Conor McGregor in 2017, he has continued to headline exhibitions around the world against a variety of opponents.
His next scheduled appearance is against former kickboxing champion Mike Zambidis in Greece. The event is currently set to proceed on June 27, although CSI’s request for an injunction introduces uncertainty regarding whether the exhibition can move forward as planned.
The lawsuit adds to a difficult week for Mayweather. ESPN reported earlier this week that the former five-division world champion is facing felony charges in connection with an alleged bad-check case.
Neither Mayweather nor representatives of his management company had publicly responded to the allegations at the time of publication.
With CSI seeking both financial recovery and court intervention, the dispute could have immediate consequences for Mayweather’s upcoming exhibition schedule.
Floyd Mayweather was sued Thursday as promoter CSI seeks repayment of $4.65 million in advances paid to the boxer for a two-fight deal to face Manny Pacquiao and Mike Tyson, according to a complaint obtained by @ringmagazine. CSI is seeking an injunction to block Mayweather’s… pic.twitter.com/7A70kW2UYI
— Mike Coppinger (@MikeCoppinger) June 19, 2026
