Heavyweight titleholder Deontay Wilder and promoter DiBella Entertainment sued Russian promoter Andrey Ryabinsky’s World of Boxing and heavyweight contender Alexander Povetkin on Monday for breach of contract and at least $5 million in damages related to the cancellation of Wilder’s mandatory fight against Povetkin.

The suit, filed in U.S. District Court for the Southern District of New York, also seeks additional damages.

Wilder was scheduled to make his fourth world title defense against Povetkin on May 21 in a much-anticipated bout at the Khodynka Ice Palace in Moscow. Povetkin, however, tested positive for the banned substance meldonium in a Voluntary Anti-Doping Association urine test conducted April 27 in Chekhov, Russia.

The results came to light nine days before the fight, which was ultimately called off while the WBC, whose title Wilder holds, investigated the matter.

Wilder was granted permission to make an optional defense, which he will do against Chris Arreola on July 16. While the WBC figures out what to do about the status of the mandatory defense, Wilder and promoter Lou DiBella want the money they would have earned against the 36-year-old Povetkin (30-1, 22 KOs).

Based on Ryabinsky’s winning purse bid of $7.15 million, Wilder was due $4,504,500 to Povetkin’s $1,930,500, with the remaining 10 percent — $715,000 — due to go to the winner. Wilder’s purse remains in escrow in a U.S. bank and the suit asks for it to be released to him.

Wilder (36-0, 35 KOs), 30, from Tuscaloosa, Alabama, also lost an undisclosed amount of money from sponsorships for the fight and incurred expenses for his training camp, which included two weeks in Sheffield, England. DiBella also wants the money he would have made from the event as well as expenses incurred.

DiBella declined to discuss the lawsuit, a copy of which was obtained by ESPN.com, other than to say, “My comment is that it speaks for itself.”

A spokesperson for Ryabinsky has not yet responded to ESPN.com’s request for comment.

The suit points out that “Ryabinsky and WOB recently secured a judgment for some $2 million in damages against Don King because his fighter, Guillermo Jones, could not participate in a World Boxing Association championship bout against a fighter promoted by WOB because Jones had ingested a banned substance, forosemide.”

Jones was due to face WOB-promoted cruiserweight Denis Lebedev in a world title fight in 2014, but the fight was canceled in the dressing room shortly before the bout because of Jones’ positive drug test. The suit argues for damages for the same reasons Ryabinsky was awarded damages in the similar case against King.

The suit also details the considerable time it took for the sides to agree on drug-testing protocol and the intense pressure the Wilder camp and DiBella — who suspected Povetkin was doping — and WBC had to put on WOB and Povetkin to get the testing started.