WASHINGTON — Federal prosecutors are planning to use DNA evidence to try to prove Rep. Ilhan Omar (D-Minn.) committed immigration fraud, as part of the sprawling investigation into the congresswoman, sources told The Post.

People familiar with the years-long criminal probe said the feds have made use of whistleblowers, government records and now obtained DNA in an effort to substantiate decade-old allegations that Omar — and possibly members of her family like her father — defrauded immigration authorities.

One source said the DNA evidence was critical to proving an allegation that Omar married her brother when she wed Ahmed Nur Said Elmi in 2009 because she was trying to help him get a green card — which never came to fruition.

It’s unclear whether the DNA was taken before or after Homeland Security Investigations (HSI) searched the congresswoman’s home in Washington, DC, last Monday, when federal agents were seen exiting the bungalow with boxes marked “Seized Property Evidence.”Another source pushed back on initial reports that investigators had gone “dumpster diving” in order to get DNA swabs of Omar, Elmi, who is currently residing in the UK, or family members.

Two more indicated that the execution of the search warrant on Oct. 12, coupled with the DNA and additional evidence, has provided a solid basis to bring charges of conspiracy to commit some form of immigration fraud before a grand jury, stemming from the probe initiated by the Minnesota US Attorney’s Office.

Given the case is being pursued as a general conspiracy, the evidence will prove useful even if some of the acts fall outside of the statute of limitations.

“If you argue a conspiracy, you can allege overt acts in furtherance of the conspiracy that are outside the statute of limitations,” said Neama Rahmini, a former federal prosecutor.

DC US Attorney Jeanine Pirro is also investigating issues related to the congresswoman’s finances — including entries in House disclosures that resulted in Omar deflating her net worth by tens of millions of dollars in the last year due to an unexplained accounting “discrepancy.”

“That judge would not have signed that warrant unless there was probable cause,” Pirro told Fox News. “If there was a crime committed, it will be prosecuted.”The DNA evidence could finally prove an allegation that has percolated in Minnesota and DC political circles for more than a decade. Omar has repeatedly denied any accusations of the rumored sibling marriage since 2016, when she was first running for office as a state representative.

Elmi, who divorced from Omar in 2017, reportedly applied and then withdrew his application for a marriage-based green card in 2019, when US Citizenship and Immigration Services asked for additional evidence about his marriage to her, according to The Washington Post.

President Trump’s border czar Tom Homan said over the weekend that the feds have built “a strong case” that could result in the Trump administration seeking to denaturalize Omar, who has lived in the US since her family emigrated from war-torn Somalia in 1995.

Previously, sources said that the immigration fraud pertained to either Omar or her father, Nur Omar Mohamed, allegedly misrepresenting the future congresswoman’s birth date so that she could become a US citizen when her dad naturalized in 2000.

Legal experts have noted the statute of limitations is lengthier for providing false information on immigration paperwork than for fraudulently marrying someone.

A marriage fraud conviction also wouldn’t jeopardize Omar’s own citizenship in the same way as a case involving false statements, a stated goal of some administration officials and one that could be proven if the alleged inaccuracies were repeated on passport renewal forms or other official government paperwork.

Rahmani said that prosecutors could attempt to prove a conspiracy to commit immigration fraud that will likely fall within a 10-year statute of limitations — or else pursue a civil case that would have no statute of limitations. Pirro has also suggested either criminal or civil counts could result from the ongoing probes.

“There’s two reasons why I think the conspiracy will be charged,” Rahmani said. “First, you have an unindicted co-conspirator in her dad, who died. … [Second,] you get some of this older conduct that’s outside the statute of limitations as well.”The ex-prosecutor added that the search warrant would not have been executed unless it had “come from the highest levels of the DOJ” and wouldn’t have been pursued unless prosecutors thought they could indict Omar.

Eventually, though, moving to strip a sitting member of Congress of their citizenship and deporting them would be an unprecedented move by the DOJ.

Her defense lawyers have said there’s “no legitimate basis for any suggestion that she has violated any law concerning her citizenship status.”Additionally, a former immigration official told The Washington Post that Omar purportedly marrying her brother had been investigated during the first Trump administration but yielded insufficient evidence.

Omar has been married three times and divorced twice. Her first marriage to Ahmed Hirsi wasn’t legally entered into until after her divorce from Elmi was finalized — despite the two having a Muslim wedding ceremony in 2002.

She gave birth to three children, the last of whom was born when she was legally married to Elmi. Omar, Elmi and Hirsi also appear to have shared the same residence at one point, per documents previously reviewed by The Post.

Further complicating the overlapping marriages, Omar filed joint taxes with Hirsi in 2014 and 2015 while still legally married to Elmi, from whom she had separated in 2011.

Omar’s father is associated with different surnames, including Nur Said Elmi Mohamed.

In 2019, the congresswoman divorced Hirsi to marry Tim Mynett, a political consultant who did work for her own campaign, following an alleged affair.

Asked last week about the seizure of evidence in his wife’s case, Mynett told Fox News: “My wife came here when she was 12 years old as a child war refugee.”As of last week, Omar also retained attorneys, who fired off a scathing letter to the Department of Justice citing “grave concerns” with the Trump administration’s investigation and demanding the “immediate return” of all seized property to the Minnesota Democrat.

The defense attorneys Amy Jeffress and Joshua Matz, who did not respond to requests for comment, wrote that the feds didn’t comply with a magistrate judge’s “special requests” for executing the search warrant at Omar’s home and flouted longstanding DOJ policy by conducting it close to an election.

“President Trump has made no secret of his desire to target Representative Omar for criminal investigation and deportation as retribution for her political advocacy,” they said.

A DOJ spokesperson replied that the letter was “riddled with false allegations and inaccuracies.”“Our attorneys and law enforcement partners complied with all court orders and legal obligations, as they always do,” the rep added. “Leaking a letter to the press right after sending it is not good faith. It is a publicity play.”