The U.S. Department of Homeland Security under former President Barack Obama found some evidence of Minnesota lawmaker Ilhan Omar’s fraudulent marriage, The New York Times reported on Thursday.

Citing current and former officials familiar with the matter, the report said that the federal investigation of Ms Omar was focused in part on whether she entered into a sham marriage in 2009 to help a man suspected of being her brother obtain a green card.

“The FBI and Department of Homeland Security investigated the marriage in summer 2016, during the Obama administration, and found some evidence that it was fraudulent,” the report stated, citing current and former officials familiar with the investigation.

Ms Omar has repeatedly denied any wrongdoing, dismissing reports of her sham marriage to her brother to bring him into America and help him obtain citizenship as lies that originated from a Somali blog.

She also accused President Donald Trump of weaponising law enforcement against her after federal agents raided her Washington, D.C., home on October 12.

The report that federal agents found evidence of her sham marriage under Mr Obama’s administration comes barely a week after Mr Obama faulted the probe into Ms Omar’s immigration record and other related matters, launched a few weeks before the midterm elections, as a political witch-hunt.

“The full weight of the federal government is being brought down on a law-abiding elected official because she has dared to criticize the president,” Mr Obama said in a post on X, describing Ms Omar’s probe as “so appalling”.

Democratic lawmakers have also opposed the investigation into Ms Omar’s alleged immigration fraud, accusing the Trump administration of weaponising federal law enforcement.

A letter dated October 26, written by Rep. Pramila Jayapal (D-Wash.) and signed by 175 House Democrats, accused the Justice Department and the Department of Homeland Security of weaponising law enforcement against Ms Omar.