According to a New York Times summary of the court appearance, van der Zwaan "acknowledged ... he lied to prosecutors about a September 2016 conversation with Rick Gates ... over work they did together for a Ukrainian political party aligned with Russian Federation".
Last year, van der Zwaan married the daughter of Ukrainian-Russian billionaire German Khan, according to the Russian editions of Forbes and Tatler magazines.
Van Der Zwaan is also accused in the charging document of deleting emails sought by the special counsel's office.
Manafort, who was Trump's campaign manager for nearly five months in 2016, and Gates, who was deputy campaign manager, were indicted by Mueller's office in October. Manafort worked on behalf of Ukrainian President Viktor Yanukovych.
The report was meant to discredit allegations that Yanukovych's Ministry of Justice prosecuted his predecessor, Yulia Tymoshenko, on illegitimate grounds.
Van der Zwaan was charged with "willfully and knowingly" making "false, fictitious, and fraudulent statements and representations" to federal investigators about his work for the law firm Skadden, Arps and Affiliates in 2012. The phone call between Van der Zwaan, Gates and Person A. was about this report, according to the Washington Post.
Skadden, Arps, Slate, Meagher & Flom said the firm fired van der Zwaan previous year, and the Federal Bureau of Investigation is now holding the Dutch citizen's passport.
Skadden's lead attorney on the project was Greg Craig, former White House counsel to President Barack Obama.
"The firm terminated its employment of Alex van der Zwaan in 2017 and has been cooperating with authorities in connection with this matter."A spokesman for Manafort declined to comment. Van der Zwaan's now-defunct LinkedIn page lists him as an associate in the London office of the law firm.
Skadden produced a report in 2012 that displayed a defiant view of the prosecution and conviction of Tymoshenko.
In court documents in the Ukranian case, Manafort is identified as having facilitated the contract for the law firm.
Skadden received a small fee for the work, just under $12,000, slightly below the amount which would have required competitive bidding. But past year, after the Justice Department began inquiring about it, Skadden refunded to the Ukrainian government $567,000 - about half of the total it was reportedly paid.
Last year, the law firm refunded $567,000 to the Ukrainian government.
The Yanukovych government hired Skadden partner and former Obama Administration White House Counsel Gregory Craig to write a report on the prosecution of Tymoshenko, assessing whether or not her imprisonment adhered to global legal standards.