Updated

The wife of a missing American former FBI agent arrived late Tuesday in Tehran seeking information about her husband, who was last seen in March at a resort island in southern Iran.

Christine Levinson and her 22-year-old son, Daniel, landed at Tehran's IKIA Airport and were received by officials from Swiss embassy, which looks after American interests in Iran in the absence of a U.S. embassy here.

According to an embassy statement, Levinson will stay in Iran until December 23.

Levinson's arrival comes after Iranian authorities said Sunday they had granted her permission and a visa to visit.

The U.S. State Department has said she planned to press the Iranian government about her husband's case.

Robert Levinson, of Coral Springs, Florida, was last seen March 8 on Kish Island where he had gone to seek information on cigarette smuggling for a client of his security firm.

Levinson, 59, a father of seven, was an FBI agent in New York and Florida until he retired in 1998.

His wife believes he is in Iran because his name has not shown up on any flight manifests of planes leaving the country and his passport has not been used anywhere.

Iran says it has informed U.S. officials through the Swiss Embassy in Tehran, that Iranian authorities have conducted an investigation, but do not know what happened to Levinson.