A former client of Debevoise & Plimpton, who is currently facing multiple U.S. Securities and Exchange Commission investigations and sought asylum in Russia, is suing the firm and three lawyers who worked on his case, alleging that they covered up a key mistake in his defense in order to preserve their own reputations.

The lawsuit, filed in the U.S. District Court for the District of Columbia on Oct. 15, alleges that in representing the plaintiffs—Mykalai Kontilai and his company Collector’s Coffee—Debevoise & Plimpton co-litigation chair Andrew Ceresney and two former associates committed negligence and malpractice. The suit alleges they failed to disclose that a document produced in the SEC investigation into Collector’s Coffee was not original, leading to criminal and civil charges against the Kontilai and his company.