US immigration agents searched the home of Minnesota Representative Ilhan Omar on Monday morning as part of a "criminal investigation".
Homeland Security Investigations (HSI) agents "executed a judicially authorized search warrant" for the home in the Washington, DC, area, a US justice department spokesperson told the BBC.
The search "is part of an ongoing federal criminal investigation," the spokesperson said, but no further details were given.
Omar was born in Somalia and came to the US aged eight fleeing war. First elected to Congress in 2018, she is running for reelection next month, and is an outspoken critic of President Donald Trump.
The US Congress is currently out of session and it is unclear if Omar was at the home. The BBC has contacted Omar for comment.
A BBC crew saw several agents at the home, some carrying boxes to a van. News of the search was first reported by Fox News, which has said the representative is being investigated over immigration paperwork filed by her late father when Omar was a child.
The nature of the criminal investigation remains unclear, but it is not the first time her immigration records have been scrutinised by Republicans. Earlier this year, fellow Congresswoman Nancy Mace of South Carolina unsuccessfully filed a subpoena of her records.
Last month, Homeland Security Secretary Markwayne Mullin told a conservative podcaster "something is going to happen", making allegations of marital fraud against Omar. Separately, the White House border tsar Tom Homan told Fox News Omar was being investigated for unspecified immigration violations.
Omar, a Democrat, denied these allegations last month. "I will say it again so it's as clear as possible: I'm not at all worried about these investigations, because they are complete shams," she said in a campaign fundraising email, an archive of which has been seen by the BBC.
She has been targeted by Trump with the president previously suggesting that she "should go back" to Somalia and that she should be deported. US citizenship is required to serve as a US House Representative.
Omar has responded to Trump's insults and attacks describing them as an "unhealthy and creepy obsession."
The president also spoke unfavourably about the Somali American community. Last week, he wrote on social media that Minnesota "is being taken over by Somali immigrants" and said "the people of Minnesota must fight back."
Republicans celebrated the search. "Nobody is above the law," said Minnesota Representative Tom Emmer. "We look forward to learning more details about this raid and investigation. ACCOUNTABILITY IS COMING!"