Ousted Wynn Macau board member Kazuo Okada is countersuing his former friend and Las Vegas casino tycoon Steven Wynn, the latest in an intensifying battle between the two that has ended a 12-year partnership.

The Japanese businessman filed the suit in a federal court in Las Vegas on Monday claiming he was wrongfully removed as a major shareholder in the casino group Wynn Resorts (WYNN).

He seeks a permanent injunction, declaratory relief and multiple claims for damages caused by those actions as well as the “improper redemption of shares,” when Wynn bought those owned Aruze USA, a subsidiary of Okada's company Universal Entertainment, at a steep 30% discount.

Okada says his ousting was a part of a fraud scheme designed to forcible take control of his stake of the company so that Wynn could enrich himself. In the suit, he identifies Wynn, as well as lawyers, financial advisers, investigators and board members as culprits in the scheme.

“Mr. Wynn and the other members of the board seek to profit from their illegal acts in a process that was corrupt and unfair, causing Universal Entertainment and Aruze USA irreparable damages,” Okada said a statement.

Wynn called the allegations “scurrilous” and said the claims fail to contain any “meaningful denial of the facts.” The company said it looks forward to having Okada's actions and its response presented to and adjudicated in court.

Their relationship turned sour after Okada filed a suit to block Wynn’s $135 million donation to a university in Macau, where he is seeking approval for a new casino. Wynn, who serves as CEO of the resort chain, later accused Okada of making improper payments to gambling regulators in the Philippines, where he too is trying to build a casino.

The animosity has grown as the race to dominate the robust Asian gaming market intensifies.

Okada was removed from the Wynn Macau board late in February after an investigation led by a former FBI director found Okada to be “unsuitable” based on the Wynn Resorts’ regulations and in violation of U.S. anti-corruption laws.

Follow Jennifer Booton on Twitter at @Jbooton