WASHINGTON ( CNN ) -- The family of a retired FBI agent who was reported missing in Iran two years ago said Monday that they remain hopeful for his return . Photos from Robert Levinson 's family show him in 2006 , left , and as he might look today . Monday marks the second anniversary of the disappearance of Robert Levinson , a father of seven children and grandfather of two . `` After two years of constantly praying for his return , we continue to anxiously await word of his whereabouts , '' said Christine Levinson , the missing man 's wife , in a statement . `` Two years [ have passed ] since our seven children and I last heard his voice , saw his warm , loving smile , and since we last hugged him hello or kissed him goodbye , '' she said . Tuesday will be Levinson 's 61st birthday . Levinson disappeared during a business trip to Iran 's Kish Island in 2007 . Iranian authorities have said repeatedly that they do not know what might have happened to him , but the claim is widely doubted in the United States . `` Since that day our family has been living a nightmare , '' Christine Levinson said . `` This has brought so much darkness to our lives . '' Christine Levinson released a computer-enhanced photograph showing what the family thinks Bob Levinson may look like today . The State Department has consistently denied Levinson was working for the U.S. government and has unsuccessfully pressed Tehran for information about his whereabouts . `` We reiterate our commitment to determining Mr. Levinson 's welfare and whereabouts , and reuniting him with his family , '' acting State Department spokesman Robert Wood said in a statement on Sunday . Congressional reaction in Levinson 's home state of Florida has been more pointed . `` On several diplomatic occasions when Bob Levinson 's name has been brought up to Iranian officials , the standard answer is , 'We do n't know anything about that . ' But the next thing out of the Iranian officials ' mouths are to discuss the matter of the Iranians held by the Americans in Irbil , Iraq , '' Sen. Bill Nelson , D-Florida , told reporters last month . `` You can draw your own conclusions , '' he said . U.S. troops arrested five Iranians accused of being members of an elite Iranian military unit during a January 2007 raid in the Iraqi city of Irbil . The Iranians were accused of supporting Shiite militias in Iraq , but Iran said they were diplomats and accused the United States of violating international law by raiding a consulate . Nelson and Rep. Robert Wexler , D-Florida , have said they plan to introduce legislation in their respective chambers calling on Iran to cooperate with the United States and come up with information about Levinson . Levinson had been working as a private investigator in Dubai . He was last heard from on March 8 , 2007 , when he checked into a Kish Island hotel and then checked out to return to the United States the following day . Wexler has said Levinson never arrived at the airport for his flight home . In December 2007 , Levinson 's wife and other relatives traveled to Iran and met with officials . Christine Levinson has said the Iranian government was polite and guaranteed her family 's security on their trip , but provided no details regarding her husband 's whereabouts . `` In the past two years , our family 's grief has grown to despair , '' Christine Levinson said . The State Department is asking anyone with information about the case to contact the department or the Levinson family via their Web site , www.helpboblevinson.com . CNN 'S Jill Dougherty contributed to this report .
Mr Levinson 's family ` ` constantly praying for his life , '' ' Mrs . Levinson disappeared two years ago during trip to Iranian island . Iran say they have no knowledge of missing man 's death . Iranian claim is widely doubted in the United States .