A US judge on Tuesday blocked federal prosecutors from searching devices seized from a Washington Post reporter as part of a leak investigation, saying he would review their contents for potential evidence.

The FBI searched reporter Hannah Natanson’s home in January as part of a national security investigation, a move that press advocates said threatened journalistic freedom.

Natanson has covered President Donald Trump’s campaign to fire hundreds of thousands of federal workers. She has not been accused of wrongdoing.

US Magistrate Judge William Porter in Virginia said in his ruling that a court-supervised review of Natanson’s devices was appropriate to balance US legal protections for journalists with the government’s right to seek evidence in criminal investigations implicating national security.

“Accordingly, the court rejects the government’s request to conduct an unsupervised, wholesale search of all … seized data,” Porter said.

Justice Department lawyers had argued the search was a necessary part of an investigation into the unlawful disclosure of US government secrets.

They said the DOJ planned to have a group of FBI agents not involved in the investigation, known as a filter team, review the seized material and separate anything not relevant to the probe.