A nonprofit organization run by President Trump’s nominee to lead a federal media agency with oversight of Voice of America and other news outlets is under investigation by the District of Columbia’s attorney general, a senior U.S. senator said Thursday.

Michael Pack is a conservative filmmaker with ties to Stephen K. Bannon whom Trump has picked to lead the U.S. Agency for Global Media. The D.C. attorney general’s office is investigating whether Pack’s use of funds from his nonprofit, Public Media Lab, was “unlawful and whether he improperly used those funds to benefit himself,” Sen. Robert Menendez (D-N.J.), the ranking Democrat on the Senate Foreign Relations Committee, said in a statement Thursday.

Menendez said the D.C. attorney general’s office informed the committee of the active investigation earlier Thursday, the same day Pack was scheduled to face a key panel vote on his nomination, before that vote was postponed. Pack has been under scrutiny for tax issues since at least September, when CNBC reported that at least $1.6 million in donations from his nonprofit were sent to his independent production company, Manifold Productions.

“For nearly eight months, Mr. Pack has refused to provide the Senate Foreign Relations Committee with documents it requested that get to the heart of the matter that the [attorney general’s office] is now investigating, or to correct false statements he made to the IRS,” Menendez said in the statement confirming the investigation. “His steadfast refusal to honor the commitment to transparency that he gave the committee at his nomination hearing forces us to ask whether Mr. Pack was actively hiding wrongdoing from the committee.”

According to Menendez, the D.C. attorney general’s office has asked the Foreign Relations Committee for documents to aid in its investigation.

David Mayorga, a spokesman for D.C. Attorney General Karl A. Racine (D), confirmed the existence of the investigation but declined to comment further.

Menendez said the committee’s chairman, Sen. James E. Risch (R-Idaho), should not have put up Pack for a key panel vote, considering the nominee’s “refusal to come clean with the Senate on his vetting issues.” He urged Risch to pause the confirmation process.

“I plan to do everything in my power to cooperate with this critical law enforcement request, and I urge Chairman Risch to do the same,” Menendez said.

The White House and Risch’s office did not immediately reply to a request for comment.

The development comes as Trump has taken a special interest in this normally obscure nomination and has ramped up criticism of Voice of America. In April, when he railed against Democratic senators, accusing them of dragging out the confirmation of his nominees, the president singled out Pack in particular.

“He’s my nominee for the CEO of the . . . Broadcasting Board of Governors,” Trump said last month, using the agency’s former name. “And he’s been stuck in committee for two years, preventing us from managing the Voice of America. Very important.”

Trump continued: “And if you heard what’s coming out of the Voice of America, it’s disgusting. . . . Things they say are disgusting toward our country. And Michael Pack would get in and he’d do a great job, but he’s been waiting now for two years. Can’t get him approved.”

The president has also pushed Senate Republicans in private, urging Majority Leader Mitch McConnell (R-Ky.) in a recent conversation to speed up consideration of Pack’s nomination, according to a person familiar with the discussion who spoke on the condition of anonymity to disclose a private conversation. The New York Times first reported on Trump’s private pressure.

The White House also attacked Voice of America last month, claiming the federally funded but independent news service had promoted Chinese government propaganda in its reporting about the coronavirus outbreak. The critique, published on the official White House website, read, “Amid a Pandemic, Voice of America Spends Your Money to Promote Foreign Propaganda.”

Amanda Bennett, Voice of America’s director, defended its independence and categorically denied any favoritism. “We have never promoted propaganda for anyone,” she told The Washington Post. “We cover stories from all different sides. That’s part of the reason we are so trusted by people around the world.”

The battle against Voice of America continued late last month, when Vice President Pence’s office threatened to retaliate against one of the agency’s reporters who disclosed that Pence’s staff had told journalists they would need masks for a visit to the Mayo Clinic in Rochester, Minn.

Pence did not wear a mask, and he later acknowledged he should have. The vice president’s wife, Karen Pence, said in a Fox News interview that he was unaware of the mask policy until after the visit, but Steve Herman, the White House reporter for Voice of America, said reporters traveling with Pence to Minnesota were told by his office in advance that they would need face coverings.

The vice president’s office told Herman that he had violated off-the-record guidance for the Mayo Clinic trip, and he was notified by the White House Correspondents’ Association that he would be barred from traveling on Air Force Two.

Fenit Nirappil contributed to this report.