A July 11 letter to FBI Director Robert Mueller from the former agent's attorney suggests CIA officials may be guilty of criminal violations involving intelligence he produced on weapons of mass destruction in 2000 that contradicted an official agency position.

The former agent's attorney, Roy Krieger, said his client initially asked the CIA's inspector general to investigate charges that CIA officials had pressured him to alter the intelligence and retaliated when he refused. But the inspector general rebuffed his request.

"If the CIA is telling him to falsify information, that's potentially a crime. This merits an investigation, and if the CIA's not going to do it, the only other place is the FBI," Krieger said.

An FBI spokesman declined to comment.

The letter to Mueller, a copy of which was obtained by Reuters on Monday, reiterates charges in a lawsuit which the former agent filed last December in Washington federal court.

Identified only by the alias "Doe," the former agent who worked as a Near Eastern specialist on counter-proliferation issues accuses the CIA of improper action on two separate pieces of intelligence.

One was the WMD intelligence the former agent says he was asked to change in 2000. The other was intelligence uncovered in 2001 that the New York Times described on Monday as dealing with Iraq's nuclear program.

The newspaper, citing people it said had knowledge of the case, said the second piece of intelligence came from a credible source and said that Baghdad had dropped a major segment of its nuclear program years before 2001.

But CIA officials refused to distribute the finding to other intelligence agencies, the Times said.

The case could shed new light on Bush administration thinking ahead of the 2003 U.S.-led invasion of Iraq, which the White House largely justified by charging that Saddam Hussein possessed weapons of mass destruction and was actively pursuing nuclear arms.

No such weapons have been found in Iraq, and U.S. arms investigators have concluded that Baghdad abandoned its nuclear-development program soon after the 1991 Gulf War.

The former CIA agent was not available for comment. Krieger declined to discuss details of the case.

A CIA spokeswoman also declined to comment.

Krieger's letter to the FBI states that CIA officials accused the former agent of sexual and financial misconduct in an attempt to discredit him and retaliate for his refusal to falsify intelligence.

The former agent was fired for unspecified reasons in September 2004, the letter says.

The former CIA agent learned in 2001 that Iraq's uranium-enrichment program had ended years before and that centrifuge components were available for examination and even purchase, the New York Times reported.

The intelligence surfaced around the time when a presidential commission on WMD intelligence says the CIA came to believe Iraq was reconstituting its nuclear program because Baghdad had sought high-strength aluminum tubes that the agency believed could be used to enrich uranium.

The Department of Energy and the International Atomic Energy Agency later concluded that the tubes were suited not for nuclear applications but for conventional rocketry.