Homeland Security Investigations agents searched the Washington, D.C., home of Rep. Ilhan Omar on Monday morning, according to three people familiar with the matter.

The Justice Department confirmed the operation in a statement, saying HSI agents executed a judicially authorized search warrant secured by the department in the Washington area.

“This enforcement action is part of an ongoing federal criminal investigation,” the Justice Department said in its statement Monday.

Two sources close to the investigation say the search stems from a criminal fraud probe into Omar’s immigration paperwork, which was completed by her late father when she was a child.

One person familiar with the probe said the investigation has been pursued for years by Homeland Security Investigations, the U.S. attorney in Minneapolis, and the Justice Department.

The search came nearly a month after White House border czar Tom Homan publicly confirmed the existence of a federal criminal investigation involving the Minnesota congresswoman.

Omar, an outspoken critic of President Donald Trump, said she was being targeted as one of the Republican’s “political enemies.”

President Trump, speaking to reporters Monday, called Omar “a terrible person” but insisted he had no involvement in the search of her home.

“I understand they’re looking at her very carefully… this has nothing to do with me,” Trump told reporters, adding, “I think she’s a terrible person, but that’s really up to the DOJ.”

The search occurred less than a month before midterm elections that will determine control of both the House and the Senate, drawing immediate and sharp condemnation from senior Democrats.

House Democratic leaders called the search “deeply disturbing” and said it “raises serious questions about the continued corrupt weaponization of the federal government against Donald Trump’s adversaries.”

Democrats also raised concerns about the timing of the action, citing longstanding Justice Department protocol discouraging overt investigative steps involving political candidates immediately before an election.

The search appears to represent exactly the kind of enforcement action that law enforcement officials have historically avoided in the weeks leading up to a major electoral contest.

Omar is the nation’s first Somali American lawmaker and has been a frequent target of immigration-related accusations from Republican lawmakers throughout her political career.