Russian billionaire Vladislav Doronin has scored victories in London and New York in a long-running dispute over a former business partner in his Aman Resorts luxury hotel chain.

Mr. Doronin’s first victory occurred earlier last week, when the High Court in London issued an order confirming the settlement between the Russian hotel operator and the U.K. liquidators of a company founded by U.S. venture capitalist Omar Amanat, Mr. Doronin’s ex-partner.

The settlement order came just days after creditors tried to push the defunct shell company and former owner of the resort chain, Aman Resorts Group Ltd., into bankruptcy in New York. An involuntary bankruptcy petition had been filed listing creditors, including Mr. Amanat and other former directors, claiming they were owed about $70 million.

Mr. Doronin on Monday described the involuntary bankruptcy as another ploy used by Mr. Amanat in their nearly two-year long scuffle over the Aman resort chain. The two former business partners bought Aman together in 2014, but the relationship soon soured and Mr. Amanat is no longer a part of the ownership.

“This has shown that Omar Amanat’s ‘signature’ is using lawyers, law firms and the media to mislead the court over and over again, and it is time people found out about his tactic,” said Mr. Doronin.

Mr. Doronin’s spokesman, Luke Chauveau, said Mr. Amanat’s “reckless actions” in filing the involuntary bankruptcy against Aman Resorts Group Ltd. “were an attempt to mislead the New York Courts through bogus creditor claims.”

The involuntary bankruptcy petition was filed by Carpenteria Management Services Ltd., an entity controlled by Mr. Amanat and considered a “renegade director on the board,” according to Mr. Chauveau.

William R. Baldiga, a bankruptcy lawyer at Brown Rudnick LLP, who initially represented Aman Resorts Group Ltd. in the involuntary bankruptcy, said in court papers he was withdrawing from the case because “it would be inconsistent with the Rule 1.16 of the New York Rules of Professional Conduct.”

The rule, a part of the New York code of conduct for lawyers, allows lawyers to end their representation of a client if they are seeking legal action “merely for the purpose of harassing or maliciously injuring any person.”

Aman Resorts Group Ltd.’s current directors—Mr. Doronin, Johan Eliasch and Alan Djanogly—have hired the law firm of Kasowitz, Benson, Torres & Friedman LLP, which is asking the U.S. judge to dismiss the involuntary bankruptcy.

“This is clearly a cynical, orchestrated attempt to harass the owners of Aman Resorts, harm the value and brand of Aman Resorts, and re-litigate issues Mr. Amanat has lost,” said Aman Resorts Group Ltd.’s current lawyer in court papers.

Mr. Baldiga declined to comment, and Brown Rudnick didn’t respond to comment. Kent Gross, a lawyer for Mr. Amanat and other creditors, declined to comment.

A hearing regarding the matter and Brown Rudnick’s withdrawal is slated for March 28 before Judge Shelley C. Chapman.

The dispute between Mr. Doronin and Mr. Amanat dates back to 2014 when the two joined to acquire Aman Resorts. The partners fell out almost immediately after inking the deal.

Following a hotel business restructuring last year, Mr. Amanat was ousted from the ownership group. Mr. Amanat had claimed Mr. Doronin illegally seized his shares and transferred them to another company.

The hotel chain operates some of the most exclusive hotels around the globe, with high profile guests that has included Mick Jagger, David Bowie, Princess Diana, Mark Zuckerberg and David Beckham.