The U.S. Federal Bureau of Investigation (FBI) has announced a reward of up to $1 million for information leading directly to the location and safe return of former FBI agent Robert A. Levinson, who disappeared from Iran's Kish Island five years ago.
In a statement, U.S. Secretary of State Hillary Clinton said Levinson's return "remains a priority for the United States" and called on Iran to "uphold its promise of assistance."
The statement also said Washington over the past year has "had reason to believe" that Levinson is being held in Southwest Asia.
Levinson's family last year released a video released by reported hostage-takers in which the former FBI agent described his captivity and asked the U.S. government for help.
The video had been e-mailed to the family in 2010 by Levinson's alleged captors, who made no demands in exchange for his release.
Levinson had retired from the FBI and was working as a private investigator when he traveled to Iran in March 2007.
His family has said that an investigation into cigarette smuggling brought him to Kish.