A Russian billionaire and Putin ally sued former Trump campaign chairman Paul Manafort and his longtime deputy Rick Gates Wednesday, alleging that the two men “siphoned for themselves millions of dollars” as part of a Ukrainian investment scheme that was paid to their “alter ego companies.”

The complaint — filed by Surf Horizon Limited, a company linked to oil tycoon Oleg Deripaska, according to Reuters — includes references to the indictment Special Counsel Robert Mueller brought against Manafort and Gates.

“In this lawsuit, Surf seeks compensatory damages for the loss suffered in an amount to be determined at trial as a result of the Defendants’ fraud, gross negligence, blatant disloyalty, and rapacious self-dealing, plus punitive damages in the amount of $25 million,” the complaint, which was filed in a New York state court, said.

Deripaska has taken legal actions against Manafort and Gates in the past, and this latest lawsuit suggested that they “testified falsely” in a deposition in one such case, brought in 2015 in the U.S District Court for the Eastern District of Virginia.

The legal tussle is over millions of dollars Manafort and Gates were said to have secured from Surf Horizon Limited in the mid-2000s, which they allegedly claimed was going to be used to invest in a Ukrainian television station called “Black Sea Cable.”

Wednesday’s complaint, echoing previous court actions by Deripaska, alleges that Manafort and Gates “vanished” $18.9 million in Surf Horizon investments, using an obscure web of companies and bank accounts.

The indictment Mueller filed against the two men, which was unsealed in late October, “provided further support for Surf’s realization that Manafort and Gates” has used some of those companies “as alter egos to wrong Surf,” the lawsuit said.

A spokesman for Manafort said in a statement that they were “surprised” by the lawsuit.

“This is a commercial matter which we thought had been addressed and resolved years ago. We will respond, if we must do so, in the appropriate manner,” the spokesman, Jason Maloni, said.

Read the lawsuit below: