The spokesman added: ‘‘It is a very important to find an FBI agent who had traveled to a free zone of Iran, which if he is found, then the U.S. should explain why the said agent has been sent to Iran and what was his mission.’’

An expert on Russian organized crime, Levinson retired from the FBI in 1998 and became a private investigator. He was investigating cigarette smuggling in early 2007, and his family has said that took him to the Iranian island of Kish, where he was last seen. Kish is a popular resort area and a hotbed of smuggling and organized crime. It is also a free trade zone, meaning U.S. citizens do not need visas to travel there.

FBI spokeswoman Jacqueline Maguire said: ‘‘As we near the sixth anniversary of his disappearance, the FBI remains committed to bringing Bob home safely to his family.’’

In an interview, Levinson’s wife said that because her husband disappeared in Iran, she believes her husband is still being held there. She doesn’t think the U.S. government has put enough pressure on Iran to release her husband.

‘‘It needs to come front and center again,’’ Levinson said. ‘‘There needs to be a lot more public outcry.’’

She said she has met with Obama and John Brennan, Obama’s counterterrorism czar and nominee to run the CIA. She said that both men pledged to do everything they could to free her husband. Now, nearly six years after his disappearance, she thinks Iran is being let off the hook.

‘‘He’s a good man,’’ she said. ‘‘He just doesn’t deserve this.’’

Meanwhile, Robert Levinson will miss another family milestone when his oldest daughter Susan gets married in February.

‘‘He’s missed so many,’’ his wife said. ‘‘It’s very upsetting.’’

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Contact the Washington investigative team at DCinvestigations (at) ap.org.

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