An internal investigation has cleared the Pentagon of violating a ban on domestic propaganda by using retired military officers to comment positively about the war in Iraq in the US media.

In a report posted on its website Friday, the Pentagon's inspector general said "we found the evidence insufficient to conclude that RMA (retired military analysts) outreach activities were improper."

The report said the controversy, which erupted in April following an expose in the New York Times, warranted no further investigation.

The Times found that the Pentagon laid on special briefings and conference calls for the retired officers, many of whom then repeated the talking points as military experts on television news shows.

It also found that many of the media analysts also worked as consultants or served on the boards of defense contracting companies, but that those ties often went undisclosed to the public.

US law bars government agencies from using funds for domestic propaganda, but the inspector general's report said the definition of propaganda is unclear.

The report said historically it has been interpreted to mean publicity for the sake of self aggrandizement, partisanship, or covert communications, and that by those standards the evidence did not show a violation of the ban.

"Further, we found insufficient basis to conclude that (the office of the assistant secretary of defense for public affairs) conceived of or undertook a disciplined effort to assemble a contingent of influential RMAs who could be depended on to comment favorably on DoD (Department of Defense) programs," it said.