Days after suggesting that U.S. Rep. Ilhan Omar should go back to Somalia, President Donald Trump weighed in publicly on allegations that she had married her brother to skirt immigration laws, a charge she has vehemently denied.

“There’s a lot of talk about the fact that she was married to her brother. I know nothing about it,” Trump said Wednesday in answer to a reporter’s question. “You' re asking me a question about that. I don’t know, but I’m sure that somebody would be looking at that.”

Trump’s remarks on the South Lawn of the White House were the first time he has discussed an unproven accusation that has been long championed by conservative opinion journalists and some GOP activists.

The accusation surfaced again as part of a recent investigation of state campaign finance violations stemming from her successful 2016 run for the Minnesota House. Documents released in that probe showed that Omar filed federal taxes in 2014 and 2015 with her current husband, Ahmed Hirsi, while legally married to but separated from Ahmed Nur Said Elmi.

Although she has legally corrected the discrepancy, she has declined to say anything about how or why it happened, fueling questions about the nature of her relationship with Elmi, a British national.

Omar has long denounced the allegation that Elmi is her brother and dismissed media inquiries about her marital history. “Whether by colluding with right-wing outlets to go after Muslim elected officials or hounding family members, legitimate media outlets have a responsibility not to fan the flames of hate,” her spokesman said in a recent statement to the Star Tribune. “Continuing to do so is not only demeaning to Ilhan, but to her entire family.”

Trump is no stranger to conspiracy theories about political opponents. He championed the idea that former President Barack Obama was not born in the U.S.; repeated tabloid accusations that 2016 GOP rival Ted Cruz had engaged in extramarital affairs, and gave credence to a story alleging that Cruz’s father was linked to the JFK assassination.

Staff reports