A US judge on Wednesday blocked federal prosecutors from searching data on a Washington Post reporter’s electronic devices seized during what one press freedom group called an “unconstitutional and illegal” raid last week.

US Magistrate Judge William B. Porter in Alexandria, Virginia—who also authorized the January 14 raid of Post reporter Hannah Natanson’s home—ruled that “the government must preserve but must not review any of the materials that law enforcement seized pursuant to search warrants the court issued.”

The government has until January 28 to respond to the Post’s initial legal filings against the agent’s actions. Oral arguments in the case are scheduled for February 6.