Former Trump campaign manager Paul Manafort and his partner Rick Gates have been sued by Russian tycoon Oleg Deripaska, who claims the two men cheated him of $18.9 million following a failed Ukrainian TV venture.

The case was filed in New York State Court on Wednesday by Surf Horizon, a firm overseen by Deripaska.

According to the lawsuit, Surf Horizon provided Manafort with $18.9 million to obtain Black Sea Cable in 2008. But as the recession took effect, Surf Horizon advised the men to sell Black Sea Cable. The men allegedly said they would.

The complaint alleges that they “took no steps to find a buyer for Black Sea Cable.” When Surf Horizon followed up about the status of the investment, Gates said that “efforts to sell Black Sea Cable were still underway.”

The lawsuit asserts that Deripaska came to find out Surf Horizon did not own Black Sea Cable as a result of his venture with the two men and that “Surf had no knowledge that Black Sea Cable had been sold or transferred to another party.”

Manafort and Gates were indicted by a federal grand jury this fall on 12 charges related to the work they did in Ukraine before joining Trump's campaign, including conspiracy against the U.S., tax fraud, and money laundering.

The lawsuit claims that “the dealings of Manafort and Gates with Surf Horizon mirror the pattern of corporate dealings alleged in the Indictment.”

Jason Maloni, Manafort’s spokesman, said the filing came as a shock.

“We are surprised by this filing,” Maloni said, according to the Washington Post. “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.”

Surf Horizon is seeking more than $25 million in damages.

Former intelligence officials said in the fall there was a good chance Manafort would seek to repay Deripaska, according to Business Insider.

The indictments against Manafort and Gates resulted from special counsel Robert Mueller’s Russia probe. Manafort and Gates pleaded not guilty at a federal courthouse hearing late last year.