Gee, how convenient. /s
I searched the net high and low and cannot even find speculation of what might be in the FBI report. The notion that this info was already out there is just a smokescreen to cover Harry's indiscretion.
On the other hand, there are lots of references on the web to Levin saying that the FBI report had bad stuff in it. Apparently, Levin had already said as much as Reid is now saying.