The daughter of missing American Robert Levinson is pleading with the U.S. and Iranian governments to help bring her father home.

Sarah Levinson said in an open letter Monday that she needs him home more than ever, to give her away at her wedding.

Tuesday is the third anniversary of her father's disappearance. He was last seen on Iran's Kish island in March 2007 where he had gone to seek information on cigarette smuggling for a client of his security firm. He had been an FBI agent in New York and Florida before retiring in 1998. He has not been seen since. Iran says it has no information on him.

His wife Christine says she believes the people of Iran can help find out what happened to him and help him come home. Anyone with information is asked to contact their Web site.

Click here to see the Levinson family's Web site.