HalderrmanFB_10.5.jpgJoe Halderman, the “48 Hours” producer accused of blackmailing David Letterman used pages from his former girlfriend’s diary which described her ongoing affair with the “Late Show” host.

A law enforcement official tells the AP that Stephanie Birkitt, who now lives in Manhattan but lived with Halderman in his Connecticut home until August, left behind her diary which Halderman is accused of using in the extortion case. Birkett worked at “48 Hours” in 1997 after graduating from Wake Forest, then returned to the “Late Show” where she’d been an intern.

The New York Post reports Birkett wrote in her diary that she continued an affair with Letterman, even after moving in with Halderman. The Post’s sources revealed Halderman and Letterman knew each other and that, “the late-night TV talk king couldn’t stand being around the guy.”

Nothing has changed with Halderman’s status with CBS News. He continues to be an employee, but remains on suspension.