A federal judge on Wednesday agreed to privately review emails related to Perkins Coie’s work on behalf of Hillary Clinton’s 2016 campaign, granting a request from Special Counsel John Durham who had challenged attorney-client privilege claims from the firm and its former clients.

U.S. District Judge Christopher “Casey” Cooper of the District of Columbia said he did not know if the emails would demonstrate that privilege was incorrectly invoked, but said it wasn’t a “significant intrusion” to conduct a review in camera.