CIA Director Richard Helms misled the FBI in June 1972 to cover up his agency's role in helping to smear the reputation of Daniel Ellsberg, the man who leaked a secret history of the Vietnam War to the press, a newly released CIA document shows.

In a June 28, 1972, memo to his deputy, Vernon Walters, Helms wrote that he asked the FBI to "desist from expanding this investigation into other areas which may well, eventually, run afoul of our operations." Those details are included in the 155-page CIA inspector general's report that was obtained through a Freedom of Information Act request by the conservative legal watchdog Judicial Watch and released Tuesday. Other elements of the document were first reported Tuesday by Fox News.

Helms' misdirection enabled the CIA's role in the Pentagon Papers case to go undiscovered for 11 months amid a growing political scandal that would eventually force President Richard Nixon from office and lead to an extensive investigation into abuses by the CIA and other parts of the U.S. Intelligence community.