O'Neill also told the inquiry in Wednesday an official report criticising relations between Scotland Yard and the media reads like an "East German ministry of information manual".
He said Elizabeth Filkin's recent review of the Metropolitan police's interactions with journalists has created a "climate of fear".
"I found this document patronising and ultimately dangerous for future accountability of the police," O'Neill added.
"It has already created a climate of fear in which police officers – who may want to pass on information that is in the public but not the corporate interest – are afraid to talk to the press.
"Despite its repeated talk of openness and transparency, the key passages in the Filkin report refer to a clampdown on 'unauthorised contact' between police and the press."
Filkin's recommendations, published in January, advised officers to avoid "flirting" and accepting alcohol from journalists.
from my personal point of view, no suggestion of impropriety would exists if public servants in 21st century Britain passed on this information in their office for no personal gain other than public interest, not even a drink!!! stay away from the pub, you are paid to work, not drink!!!! it really is that simple