An American man who disappeared in Iran more than six years ago had been working for the CIA in what U.S. intelligence officials describe as a rogue operation that led to a major shake-up in the spy agency.

Bob Levinson, an ex-FBI agent, traveled to the Iranian Island of Kish in March 2007 to investigate corruption at a time when he was discussing the renewal of a CIA contract he had held for several years. He also inquired about getting reimbursed for the Iran trip by the agency before he departed, according to former and current U.S. intelligence officials.

After he vanished, CIA officials told Congress in closed hearings as well as the FBI that Levinson did not have a current relationship with the agency and downplayed its ties with him. Agency officials said Levinson didn't go to Iran for the CIA.