FBI renews $1 million reward for return of agent missing in Iran

The US Federal Bureau of Investigation has renewed a $1 million reward for information leading to the safe return of a former agent who went missing in Iran six years ago.

Robert Levinson traveled to the Iranian island of Kish on March 8, 2007 as a private investigator looking into cigarette smuggling. He went missing the following day and has not been seen or heard from since.

The 28-year-veteran of the FBI will turn 65 on March 10. He retired from the agency 10 years ago.

A year ago the FBI offered a $1 million reward for information leading to his safe return home.

"That reward still remains unclaimed, and I again encourage anyone with information about Bob's disappearance to contact us," FBI deputy director Sean Joyce said in a statement.

Levinson, a father of seven, suffers from diabetes and high blood pressure. His family is worried he may not be getting proper medical treatment.

In 2011 the State Department cited reports that he was being held in Southwest Asia in the border region of Afghanistan, Iran and Pakistan.

Several times the United States has sought explanations from Iran but the Iranians have said they know nothing about Levinson's whereabouts.