A 33-year-old attorney fired last year by a prominent international law firm became the fourth person to plead guilty in special counsel Robert Mueller’s Russia investigation, admitting Tuesday that he lied to federal investigators about his contacts with a Trump campaign official.

Alex van der Zwaan, who worked at the law firm Skadden, Arps, Slate, Meagher & Flom, admitted in Washington’s federal court Tuesday to making false statements about his interactions with former Trump campaign aide Rick Gates. His plea deal may allow him to avoid prison.

Van der Zwaan’s plea comes on the heels of an extraordinary indictment from Mueller last week that charged 13 Russian individuals and three Russian companies in a hidden but robust social media effort that provoked on-the-ground rallies and sought to meddle in the 2016 U.S. presidential election by denigrating Democrat Hillary Clinton and boosting the successful campaign of Republican Donald Trump.

But the charge against the attorney, who is also the son-in-law of a Russian billionaire, does not involve election meddling or relate to the Trump campaign’s operations. Instead, it stems from the special counsel’s investigation into Paul Manafort, Trump’s former campaign chair, and Gates, who is a longtime business associate of Manafort.

Gates and Manafort were indicted last year on charges that they conspired to launder millions of dollars and directed a covert Washington lobbying campaign on behalf of pro-Russian Ukrainian interests. Both men have pleaded not guilty.

On Tuesday, van der Zwaan, a Dutch citizen who authorities say lives in London, admitted to lying to federal investigators while they questioned him about the production of a report that Manafort and Gates are accused of secretly funding by funneling $4 million through an offshore account.

The report, authored by Skadden Arps, focused on the trial of former Ukrainian Prime Minister Yulia Tymoshenko, a political foe of former Ukrainian President Viktor Yanukovych, whose political party was a client of Gates and Manafort.

The false statements van der Zwaan admitted to making involved the timing of his last communication with Gates and a person, described as “Person A,” who was a longtime business associate of Manafort and Gates in Ukraine.

According to court papers attached to his plea agreement, the conversations, including some using encrypted applications, occurred in September 2016 and involved possible criminal charges being brought in Ukraine against a former Ukrainian official, Manafort and “Law Firm A,” an apparent reference to Skadden Arps.

The Nov. 3, 2017, questioning of van der Zwaan occurred just days after Manafort’s indictment and, according to court papers, while prosecutors still were investigating potential violations of the Foreign Agents Registration Act.

The charge against van der Zwaan carries a maximum sentence of five years in prison, though sentencing guideline ranges discussed in court placed the more likely punishment from zero to six months.

In addition to the false statements, court papers reveal that in late July or early August of 2012, van der Zwaan, without authorization, gave an advance draft of the Tymoshenko report to a public relations firm working for the Ukrainian Ministry of Justice. In September 2012, he also provided Gates with talking points for use in a public relations campaign.

On Tuesday, Skadden Arps released a statement saying it had fired van der Zwaan last year, and it “has been cooperating with authorities in connection with this matter.”

“The conduct to which Alex has pled guilty is contrary to our values, policies and expectations,” the firm added.

Last year, van der Zwaan married the daughter of Ukrainian-Russian billionaire German Khan, according to the Russian editions of Forbes and Tatler magazines.

Khan, who was born in Kiev, shares control of one of Russia’s biggest financial and industrial investment conglomerates, Alfa Group, with fellow billionaires Mikhail Fridman and Alexei Kuzmichev. Forbes estimates Khan is worth about $10 billion.

Khan and his partners are suing Buzzfeed News over its publication of a dossier of allegations about ties between Trump and Russia. The dossier, which is a collection of memoranda authored by former British spy Christopher Steele, makes several claims about Alfa Group that the partners say are false and defamatory.

Buzzfeed is fighting the lawsuit. The dossier has become a political lightning rod because Steele’s work was funded in part by Clinton’s campaign and the Democratic National Committee. Parts of Steele’s work were also used in obtaining a secret warrant to monitor Carter Page, a former Trump campaign foreign policy adviser.

(AP)