WASHINGTON (CN) – In one of the cases being prosecuted by Special Counsel Robert Mueller, the government asked a federal judge Monday to uphold a provision of a plea agreement that limits public access to the records.

The request to the court came one day before U.S. District Judge Amy Berman Jackson will sentence Alex Van Der Zwaan, who pleaded guilty on Feb. 14 to lying to FBI agents about his contacts with former Trump campaign associate Rick Gates.

As part of his plea deal, Van Der Zwaan had agreed to waive his right to receive or request information from the government pertaining to its investigation or prosecution of the case under the Privacy and Freedom of Information Acts.

Justice Department attorney Andrew Weissmann noted in a 3-page filing late Monday morning that the waiver “serves manifold legitimate criminal-justice interests while minimally encumbering Van Der Zwaan’s rights for a period of limited duration.”

Among other things, Weissmann argued, the waiver would prevent Van Der Zwaan “from taking further actions that could interfere” with the special counsel’s work.

Special counsel Mueller is investigating Russian interference in the 2016 U.S. election, along with possible ties between Russia and the Trump campaign.

Weissman’s April 2 filing also expresses concern about the disclosure of nonpublic information that is part of the special counsel’s ongoing investigation.

“Van Der Zwaan is in an unusual position of having information related to the Office’s investigation that is not widely known – including information that he knows first-hand due to his role in the conduct the Office is investigating,” the filing says.

“And requests filed by someone with non-public information could, themselves, suggest to third parties investigative facts that are otherwise not widely know,” the filing continues.

Mueller’s team says Van Der Zwaan, 33, worked closely with Gates and former Trump campaign chair Paul Manafort on a report commissioned by the Ukrainian government about the trial of Yulia Tymoshenko, the former prime minister of Ukraine.

The special prosecutor has charged Manafort and Gates with tax and bank fraud, conspiracy, money laundering, and failing to register as foreign agents for the work they did for the Ukrainian government.

Gates has since pleaded guilty to one count of lying to the FBI and is cooperating with Mueller.

Prosecutors say Van Der Zwaan repeatedly lied about his communications with Gates and with a Ukrainian business associate of both Manafort and Gates, who is identified only as “Person A” in the filing.

According to a March 27 filing from the special counsel’s office, “Person A has ties to a Russian intelligence service and had such ties in 2016.” That timeline, according to the March 27 filing, was “material” to the special counsel’s investigation.

Van Der Zwaan had admitted he knew of the connection, according to the March 27 filing, telling investigators during his first interview with Mueller’s team that Gates told him Person A was an intelligence officer with the GRU, Russia’s main intelligence directorate.

In his own sentencing memo, meanwhile, Van Der Zwaan said he was motivated to lie to investigators to conceal the fact that he had recorded conversations with Gates and Person A, who had told him the new Ukrainian government might file charges against him, along with attorneys at his former law firm Skadden, Arps, Slate, Meagher & Flom LLP, with whom he worked on the Tymoshenko report.

Cooley LLP attorney William Schwartz signed this March 27 memo for Van Der Zwaan. The New York attorney has not responded to an email seeking comment.

In its short filing Monday, the government asked the court to ignore D.C. Circuit precedent in Price v. United States, which it says held that waivers of constitutional rights as part of a guilty plea “are not enforceable where the government cannot articulate legitimate criminal-justice interests for the waiver.”

“Given that ambiguity and the novelty of Price … we respectfully suggest that the Court not extend Price into this new context,” the filing says.

The special counsel’s office declined to comment beyond what its attorneys wrote in the filings.