The Central Intelligence Agency on Friday denied allegations by an ex-spy that it had sought information on a US professor who was critical of the Iraq war in order to discredit him.
Glenn Carle, who served as a top CIA counter-terrorism official, had told The New York Times that Bush administration officials twice sought to investigate Juan Cole, a history professor and widely read blogger.
Carle detailed two occasions in which he was approached by colleagues who were looking for information to discredit Cole, a professor at the University of Michigan, despite a legal ban on the agency spying on Americans.
CIA spokesman Preston Golson denied the allegations.
"We've thoroughly researched our records, and any allegation that the CIA provided private or derogatory information on Professor Cole to anyone is simply wrong," he said.
"We value the insights of outside experts, including respected academics, who follow many of the same national security topics we do. Diversity of thought is essential to the business of intelligence analysis."
In a post on his "Informed Comment" blog on Thursday, an outraged Cole said he had been targeted for exposing "propaganda" by former president George W. Bush's administration and called on Congress to investigate the matter.
He also wrote that around the time of the alleged requests he began receiving less invitations from Washington think tanks to speak to audiences that included intelligence analysts and counterterrorism officials.
The Times cited intelligence officials as saying that they had asked an analyst for information on Cole in 2006 because White House officials wanted to know why he had been invited to CIA-sponsored conferences.
But on Friday a senior intelligence official insisted Cole "has participated in CIA conferences in the years since this alleged series of events -- in both the Bush and the Obama administrations."
"It's the smart thing -- and the right thing -- for American intelligence agencies to hear from smart people," the official said.