This undated handout photo provided by the family of Robert Levinson after they received it in April 2011, shows retired-FBI agent Robert Levinson. Levinson Family/AP

An American who went missing in Iran six years ago worked for the CIA and was not in the country on a business trip as U.S. officials had claimed, U.S. media reported Thursday.

In a case that had long been shrouded in secrecy and vague official accounts, The Associated Press and The Washington Post published lengthy reports revealing how retired FBI agent Robert Levinson had been paid by the CIA to gather intelligence around the world.

Levinson flew to an Iranian resort, Kish Island, in March 2007 to investigate corruption in the country, with hopes of also gleaning information about Tehran's suspected nuclear program, the reports said.

But he vanished, and U.S. officials have publicly said that he was a private citizen traveling on private business.

Months later, information surfaced through emails and other documents that Levinson had, in fact, been hired to go to Iran by the CIA — but by a rogue team of analysts with no authority to run overseas operations.

In violation of CIA rules, the analysts had hired Levinson — a seasoned FBI agent with expert knowledge about Russian criminal circles — to gather intelligence, the AP and the Post wrote.

When Congress finally learned what had taken place, the agency sacked three analysts and seven others faced disciplinary action.

To pre-empt a potentially embarrassing lawsuit, the Central Intelligence Agency also paid Levinson's family $2.5 million.