FILE PHOTO - Paul Manafort, former campaign chairman for U.S. President Donald Trump, departs after a bond hearing as part of Special Counsel Robert Mueller's ongoing Russia investigation, at U.S. District Court in Washington, U.S., December 11, 2017.

(Reuters) - U.S. President Donald Trump’s former campaign manager Paul Manafort faced a new legal headache on Wednesday after a Cyprus-based company tied to a Russian oligarch sued him and his business partner Richard Gates over allegations they committed financial fraud by misappropriating millions of dollars.

Surf Horizon Limited, a company linked in corporate filings to ally of Russian President Vladimir Putin named Oleg Deripaska, accused Manafort and Gates of misappropriating more than $18.9 million that the company had invested in Ukrainian telecom companies known collectively as the “Black Sea Cable.”

Manafort and Gates are already under criminal indictment by Special Counsel Robert Mueller, who has accused them of failing to register as foreign agents, conspiring to commit money launder and conspiring to defraud the United States.

Wednesday’s lawsuit, brought against the pair in a New York state trial-level court, marks the second time now that the Deripaska-linked company has sued them along with Pericles Emerging Market Partners, an investment management firm controlled by Manafort and Gates.

In August 2015, the company also filed a parallel case in the U.S. District Court for the Eastern District of Virginia, seeking documents and depositions in connection with the alleged missing money.

Lawyers for Manafort and Gates could not immediately be reached for comment.

According to the lawsuit, Manafort and Gates had testified under oath in 2015 that they did not know whether Surf Horizon still owned any stock in the Black Sea Cable, even though Surf claims had paid one of their affiliated companies $7.35 million in management fees.

The lawsuit says Manafort and Gates said in sworn testimony they did not know what happened to more than $26 million had gone missing from the investment.

In May 2017, however, one of Surf’s affiliates, known as Adoptol Limited, brought legal proceedings in Cyprus and unearthed documents which show that Manafort and Gates had “siphoned off for themselves millions of dollars” from Surf’s investment, the lawsuit said.