WASHINGTON (CNN) -- Iran may be holding a former FBI agent in a bid to exchange him for Iranians seized by U.S. troops in Iraq in 2007, a U.S. senator suggested Tuesday. Christine Levinson, wife of Robert Levinson, went to Tehran in 2007 to try to learn her husband's fate. Robert Levinson disappeared from Iran's Kish Island in March 2007. Iranian authorities have repeatedly said they don't have any information on him, but that is widely doubted in the United States. "On several diplomatic occasions when Bob Levinson's name has been brought up to Iranian officials, the standard answer is, 'We don'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. "You can draw your own conclusions."
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Robert Levinson disappeared almost two years ago from Iranian island
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Florida congressman, senator seek new attention from Obama administration
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Senator says Iranians caught in Iraq always mentioned in conjunction with Levinson
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Iranians say they have "zero knowledge" of missing man's whereabouts
"So, again, we call on the @placeholder to provide whatever information they have on Mr. Levinson so that we can hopefully return this gentleman to his family."