Researcher Ashkan Soltani giving a talk. Image: Data Days/Flickr

Barely a month after his appointment, security reseasrcher and former FTC chief technologist Ashkan Soltani is leaving his post as a White House senior advisor, apparently unable to get security clearance from the US government.

Government officials have not commented on the nature of Soltani’s departure, or why he was not cleared—a White House spokesperson merely told The Guardian’s Danny Yardon that “his detail has ended”—but many have speculated it is due to his work reporting on documents leaked by former NSA intelligence contractor Edward Snowden.