Tyler S. Drumheller, a high- level CIA officer who publicly battled agency leaders over one of the most outlandish claims in the U.S. case for war with Iraq, died Aug. 2 at a hospital in Fairfax County, Virginia. He was 63.

The cause was complications from pancreatic cancer, said his wife, Linda Drumheller.

Drumheller held posts in Africa and Europe over a 26-year career during which the CIA’s focus shifted from the Cold War to terrorist threats. He rose to prominent positions at CIA headquarters, serving as chief of the European division at a time when the agency was abducting al-Qaida suspects on the continent and U.S. allies there faced a wave of terrorist plots.

But he was best known publicly for his role in exposing the extent to which a key part of the administration’s case for war with Iraq had been built on the claims of an Iraqi defector and serial fabricator with the fitting code name “Curveball.”

In contrast to Hollywood’s depiction of spies as impossibly elegant and acrobatic, Drumheller was a bulky, rumpled figure who often seemed oblivious to the tufts of dog hair on his clothes.

“I always thought of him as an overfed George Smiley,” said Bill Murray, a former CIA colleague, referring to the character in John le Carré spy novels known for his espionage acumen but unassuming appearance.

Drumheller spent the bulk of his career as an undercover officer seeking to avoid public attention. But after retiring in 2005, he emerged as a vocal critic of the George W. Bush administration’s use of deeply flawed intelligence to build support for its decision to invade Iraq in 2003.

The blow-up over Curveball coincided with Drumheller’s retirement from the CIA. “I think he was really proud of standing up against the war,” Linda Drumheller said in an interview. “That was his personal greatest achievement.”

The son of an Air Force chaplain, Drumheller was born in Biloxi, Mississippi, on April 12, 1952. He spent part of his childhood in Germany before attending the University of Virginia.