WASHINGTON (CBS)—A manhunt is underway for a traitor inside the Central Intelligence Agency, CBS News has learned.

The  CIA and FBI are reportedly conducting a joint investigation into one of the worst security breaches in CIA history.

READ MORE: What We Know About 17-Year-Old Latif Williams, Wanted For Murder Of Temple Student Samuel Collington

CBS News reports that the alleged traitor exposed thousands of top-secret documents that described CIA tools used to penetrate smartphones, smart televisions and computer systems.

READ MORE: Brotherly Love: For Nearly 50 Years, Musicopia Giving Philadelphia Children Gift Of Music

Sources say authorities are looking for an insider—either a CIA employee or contractor — who had physical access to the material.

MORE NEWS: Trevor Noah To Host 'The 64th Annual GRAMMY Awards' On CBS

Read more on CBS News.