“We have received recent indications that Bob is being held somewhere in southwest Asia,” said Clinton who has long urged Iran to help in the case and met with Levinson’s wife.
“We respectfully request the Iranian government to undertake humanitarian efforts to safely return and reunite Bob with his family,” the chief US diplomat said in a statement.
Noting that Iran has in the past offered to help locate Levinson, Clinton said: “We would appreciate the Iranian government?s efforts in this matter.”
Mystery shrouds the fate of Levinson who disappeared on Iran’s Gulf island of Kish in March 2007.
Last month Iran’s elite military force, the Revolutionary Guards, denied it was holding Levinson, as reported on some websites.
Iranian officials have previously denied having any information about the missing American’s whereabouts.
Christine Levinson says her husband, who retired from the FBI more than a decade ago, had traveled to Kish island to investigate cigarette counterfeiting in the region and was last heard from on March 8, 2007.
The mystery of his disappearance is a further strain in relations between the United States and Iran, which remain tense over Iran’s nuclear drive and the fate of other Americans in Iran.
Shane Bauer, Josh Fattal and Sarah Shourd went on trial last month more than 18 months after they were arrested on the unmarked border with Iraq.
Shourd was tried in absentia after she was freed and returned home last September on bail of around $500,000.
