The grand jury subpoenas were issued in Minnesota as federal authorities gather evidence in the inquiry, said the person, who spoke on condition of anonymity because they were not authorized to discuss an ongoing investigation.
The investigation led federal agents to search Omar's Washington DC home on Monday, just weeks before the November midterms, in which the Democrat is seeking re-election. The scope of the inquiry remains unclear, though Homeland Security Secretary Markwayne Mullin has suggested authorities were examining potential crimes related to her family's immigration paperwork.
On Tuesday, Jeanine Pirro, the US attorney for the District of Columbia, said in a Fox News interview that "there are several investigations going on" related to Omar, including issues concerning the lawmaker's financial disclosures. "If there was a crime that was committed, it will be prosecuted," Pirro said.
Democrats swiftly condemned the search, accusing the administration of targeting Omar for political purposes. In a statement on X, Omar called the search an "attempt to target political enemies and weaponize federal law enforcement."
"For 10 years, Trump has targeted me with baseless lies and smear campaigns. This is just the latest escalation in his campaign of political intimidation," she said. "I will not be silenced."
A phone message seeking comment was left with a representative for Omar. The search notably took place three weeks before the midterms, despite the Justice Department's historical practice of avoiding public investigative actions involving a candidate within 60 days of an election.
Omar, first elected to the House in 2018, represents Minnesota's fifth district, including Minneapolis. She is part of "the Squad" of progressive lawmakers, was one of the first two Muslim-American women in the House, and is the first African refugee elected to Congress.