The State Department said Tuesday that a letter it sent this week to the Iranian government seeking information about a missing American in Iran is its second inquiry into the man's welfare and whereabouts in a month.
Spokesman Sean McCormack said the department first asked about the case March 12, shortly after the former FBI agent was reported missing, but it had not received any credible information in response.
As a result, the department on Monday sent a letter to authorities in Iran asking for help in locating the man, he said.
A U.S. official familiar with the case identified the missing former FBI agent as Robert Levinson. The official, speaking on condition of anonymity because he is not authorized to speak publicly about the case, said Levinson was on or near the Island of Kish when last heard from.
Both State Department inquiries to Iran were placed through the government of Switzerland, which represents U.S. interests in Iran. However, the initial outreach, which involved asking the Swiss Embassy in Tehran to look into the matter, was not public knowledge until Tuesday, McCormack said.
"I don't know specifically with whom they (the Swiss) interacted in the Iranian government," he told reporters. "I do know that they have gotten back to us and said they don't know his welfare and whereabouts."
The FBI said Monday that Levinson retired from the bureau nearly a decade ago and was in Iran on private business. He was last seen in Iran in early March and was not working for the FBI as a contractor, the agency said.
He was last heard from in a coastal area of southern Iran on or near Kish Island, where he was apparently working on a project for an independent filmmaker, officials said.
McCormack refused to say if the decision to make a written appeal directly to the Iranians reflected increased concern about the missing man, whom he declined to identify for a second day due to privacy concerns.
He confirmed the letter had been given to the Swiss but could not say whether the Swiss had delivered it to the Iranians.
U.S. citizens are not barred from traveling to Iran but they must obtain a visa even though Kish Island is a Persian Gulf resort area and free-trade zone for which no Iranian visa is required.