Attorney Alex van der Zwaan (L), who formerly worked for the Skadden Arps law firm, arrives at a U.S. District Courthouse for his sentencing April 3, 2018 in Washington, DC.

The first sentencing in special counsel Robert Mueller's Russia probe has been handed down.

A federal judge on Tuesday sentenced Dutch lawyer Alex van der Zwaan to 30 days in prison and $20,000 in fines. He will voluntarily surrender, and will be held to two months of supervised release.

Van der Zwaan had pleaded guilty to lying to the FBI as part of Mueller's investigation of Russian meddling in the 2016 election and possible collusion between the Trump campaign and the Kremlin.

In a court filing about van der Zwaan's sentencing last week, the special counsel's office said the Dutch lawyer and Rick Gates, a top campaign aide to Donald Trump, had numerous calls during September and October 2016 with a "close business colleague" of Gates and former Trump campaign boss Paul Manafort.

Mueller alleged that Gates told van der Zwaan that the colleague, identified in the memo as "Person A," is a former spy with Russian military intelligence wing GRU.

The participants in the late-2016 conversations allegedly discussed the compensation for van der Zwaan's law firm, Skadden Arps, over its involvement in crafting a report bolstering Ukrainian President Viktor Yanukovich and undermining political opponents. They also allegedly talked about the possibility of being charged with crimes for the report.

Lawyers for van der Zwaan did not immediately respond to CNBC's requests for comment.

While van der Zwaan is the first to be sentenced in the investigation, the special counsel has already collected five guilty pleas and more than a dozen indictments since Mueller was appointed by Deputy Attorney General Rod Rosenstein in May.

Gates, who worked alongside Manafort on the campaign and as a business partner, pleaded guilty in February to conspiracy against the U.S., as well as one count of making false statements to federal investigators.

Manafort, who has been charged with dozens of counts in multiple indictments, including money laundering and bank fraud, has maintained his innocence. His trial is scheduled to start in July.

In a recent court filing, Mueller alleged that Manafort committed crimes by "colluding with Russian government officials with respect to the Russian government's efforts to interfere with the 2016 election."