The U.S. State Department did not respond to a request for comment about Iran’s acknowledgement.

Levinson disappeared from Iran’s Kish Island on March 9, 2007, The Washington Post reported. For years, U.S. officials would only say that Levinson, a meticulous FBI investigator credited with busting Russian and Italian mobsters, was working for a private firm on his trip.

In December 2013, the AP revealed Levinson in fact had been on an unauthorized mission lead by at least three veteran CIA analysts who were subsequently forced out of the agency. The CIA also disciplined seven others in relation to the rogue spy operation.

Levinson’s family had received a $2.5 million annuity from the CIA in order to stop a lawsuit revealing details of his work.

Since his disappearance, the only photos and videoof Levinson emerged in 2010 and 2011. He appeared gaunt and bearded with long hair, and was wearing an orange jumpsuit similar to those worn by detainees at the U.S. prison at Guantanamo Bay.

The video, with a Pashtun wedding song popular in Afghanistan playing in the background, showed Levinson complaining of poor health.

Rumors about him have circulated for years, with one account claiming he was locked up in a Tehran prison run by Iran’s paramilitary Revolutionary Guard and U.S. officials suggesting he may not be in Iran at all.

An FBI poster showing a composite image of former FBI agent Robert Levinson, (R) of how he would look like now after five years in captivity, and an image, (L) taken from the video, released by his kidnappers, Tuesday, March