A former business associate of President Donald Trump who has extensive ties to organized crime is cooperating with a money laundering probe that stretches across three continents, the Financial Times reported Thursday.

The Russian-born Felix Sater is working with a team of lawyers and private investigators who are pursuing civil cases against the Khrapunovs, a Kazakh family that Sater allegedly helped use shell companies to launder millions of dollars into U.S. real estate, five people with knowledge of the probe told FT.

One of the venues for that dirty money, according to the report, was a failed Manhattan real estate venture of the President’s, Trump SoHo:

It is unclear how much money has flowed from the alleged Kazakh laundering scheme to Mr Trump. Title deeds and banking records show that in April 2013 shell companies controlled by the Khrapunovs spent $3.1m buying three luxury apartments in Trump Soho from a holding company in which Mr Trump held a stake.

The FBI also was interested in whether the probe involved potential money-laundering in the United States, one anonymous source involved in the investigation told the FT.

Viktor Khrapunov and Mukhtar Ablyazov, two of the deep-pocketed individuals accused of money laundering by the Kazakh government, say they are innocent victims of a political vendetta, according to the FT. Sater declined to comment to the newspaper.

Alan Garten, a lawyer for the Trump Organization told FT last year that he had “no doubt” that “every legal requirement” was met in conducting due diligence on financial transactions involving Trump properties.

Trump’s business ties to Sater, who once served 15 months in prison for stabbing a stockbroker in the face with a broken martini glass and went on to became a government informant after pleading guilty in a $40 million fraud scheme, have long raised eyebrows.

Sater and Tevfik Arif, a Kazakh banker who worked in the Soviet Union, collaborated with Trump through their real estate company Bayrock to find buyers for the hotels and condos branded with the Trump name. Sater also visited Moscow with Ivanka Trump and Donald Trump, Jr. in the mid-2000s to scout a site for a Trump Tower there, a project that never came to fruition.

Earlier this year, Sater reportedly played a role in helping put together a “peace plan” drawn up by a member of Ukraine’s parliament. That plan, which called for lifting U.S. sanctions against Russia, was reportedly hand-delivered to the White House by Trump’s personal lawyer, Michael Cohen.