Mohammed Tasleem, a clandestine operative of the spy agency ISI, had been posing as an FBI agent to extract information from Pakistanis living in the US and was issuing threats to keep them from speaking openly about Pakistan`s government, The New York Times reported.
His activities were part of what government officials in Washington, along with a range of Pakistani journalists and scholars, say is a systematic ISI campaign to keep tabs on the Pakistani diaspora inside America.
Tasleem collected information in a variety of ways, and that on at least one occasion he passed himself off as an FBI agent to get information from one Pakistani living in the US, an American official, who was briefed on the episode, told the Times.
The FBI brought Tasleem`s activities to Leon Panetta, then the director of the CIA, and last April, Panetta had a tense conversation with ISI chief Lt Gen Ahmed Shuja Pasha.
Within days, Tasleem was spirited out of America, a quiet resolution typical of the spy games among the world`s powers.
But some of the secrets of that hidden world became public last week when Kashmiri American Council director Fai, along with another man, working for a charity that the FBI believes is a front for Pakistan`s spy service were indicted.
62-year-old Fai, a US citizen, was arrested by the federal agency last week on charges of being an ISI agent who lobbied for the ISI and Pakistan army on the issue of Kashmir.
The agency had filed a 43-page affidavit in a US court in connection with the indictment of Fai and another US citizen Zaheer Ahmad, 63, as agents of Pakistan.
The investigation exposed one part of what American officials say is a broader campaign by the ISI to exert influence over lawmakers, stifle public dialogue critical of Pakistan`s military and blunt the influence of India, the report said.
American officials said that compared with countries like China and Russia ? whose spies have long tried to steal American government and business secrets ? the ISI`s operations here are less extensive and less sophisticated. And they are certainly far more limited than the CIA`s activities inside Pakistan.
Even so, officials and scholars say the ISI campaign extends to issuing both tacit and overt threats against those who speak critically about the military.
The ISI is widely feared inside Pakistan because of these very tactics. For example, US intelligence officials believe that some ISI operatives ordered the recent killing of a Pakistani journalist Saleem Shahzad.
At the same time, the Pakistani spy agency remains a close ally of the CIA in the hunt for operatives with al Qaeda. It is a relationship that often complicates the ability of the US to put pressure on Pakistan to alter its tactics.
Several Pakistani journalists and scholars in the US interviewed over the past week said that they were approached regularly by Pakistani officials, some of whom openly identified themselves as ISI officials.
They said the officials caution them against speaking out on politically delicate subjects like the indigenous insurgency in Baluchistan or accusations of human rights abuses by Pakistani soldiers. The verbal pressure is often accompanied by veiled warnings about the welfare of family members in Pakistan, the journalists and scholars said.
One Pakistani journalist, who like the others asked to be quoted anonymously because of concerns about his safety, recalled an episode in December 2006 in which a Pakistani man filmed a public discussion about Pakistan`s tribal areas at the Kennedy School of Government at Harvard. The event`s organisers later learned the man was from the ISI, the journalist said.
Another Pakistani author said at several conferences and seminars in recent years, representatives from the spy agency made their presence known by asking threatening questions.
"The ISI guys will look into your eyes and will indirectly threaten you by introducing themselves," the author said. "The ISI makes sure that they are present in every occasion relating to Pakistan, and in some cases they pay ordinary Pakistanis for attending events and pass them information."
In a way, the activities of the ISI in the US reflect the paranoia among officials in Islamabad that Pakistan`s influence in the US has been eroding steadily because of a barrage of negative news accounts about Pakistan`s military and efforts by India to jockey for influence in Washington.