A US judge on Friday denied Mahmoud Khalil’s request to be released from detention, after federal prosecutors changed their rationale for holding the Columbia graduate student as part of their crackdown on anti-Israel, pro-Palestinian activists.

Newark, New Jersey-based US District Judge Michael Farbiarz on Wednesday said the government could not use foreign policy interests to justify Khalil’s detention.

Following his decision, on Friday, the government said it was also holding Khalil, a legal permanent resident of the United States, on a charge of immigration fraud.

In response, Farbiarz said Khalil’s lawyers had not successfully argued why it was unlawful for the government to hold him on that charge, which he has denied.

The ruling marked the latest turn in Khalil’s fight to be freed from a Louisiana detention center after his March arrest for involvement in the anti-Israel, pro-Palestinian protest movement, which US President Donald Trump has called antisemitic. His detention was condemned by civil-rights groups as an attack on protected political speech.

Marc Van Der Hout, a lawyer for Khalil, said the government practically never detained people for immigration fraud, and the Syrian-born student was being punished for opposing Israel’s US-backed war in Gaza following Hamas’ October 2023 assault on southern Israel that killed some 1,200 people and saw another 251 taken hostage.

“Detaining someone on a charge like this is highly unusual and frankly outrageous,” said Van Der Hout. “There continues to be no constitutional basis for his detention.”

Farbiarz had previously suggested legal residents like Khalil were rarely detained on the basis of immigration fraud. On Friday, he said Khalil should seek bail from the immigration lawyer in his case.

Khalil was arrested on March 8 by immigration agents in the lobby of his university residence in Manhattan after the State Department revoked his green card. He has since been held in immigration detention in Louisiana.

The US administration says it revoked Khalil’s green card under a little-used provision of US immigration law allowing the deportation of any noncitizen whose presence in the country is deemed by the US secretary of state to be adverse to US foreign policy interests. Khalil’s lawyers said his arrest and attempted deportation violated his right to free speech under the US Constitution’s First Amendment.

Farbiarz had previously blocked the administration from deporting Khalil while his challenge to the constitutionality of his arrest played out. On May 28, the judge ruled that the foreign policy provision cited by the Trump administration was so vague that it was likely unconstitutional, and on Wednesday, he ruled that the administration could not use that provision to justify Khalil’s detention.

Khalil was the first foreign student known to be arrested as part of Trump’s bid to deport foreign students who took part in pro-Palestinian, anti-Israel protests that swept US college campuses.

Khalil isn’t accused of breaking any laws during the protests at Columbia, but the Trump administration has argued that noncitizens who participate in such demonstrations should be expelled from the country. They say such protesters express views that are antisemitic and pro-Hamas.

Khalil’s US citizen wife, Dr. Noor Abdalla, gave birth to the couple’s first child while Khalil was detained in April.