CORAL SPRINGS, Fla, (WSVN) — A South Florida family is demanding answers after their loved one, the longest held civilian hostage in U.S. history, was not among the Americans released by Iran on Saturday.

It has been 3,233 days since Coral Springs resident Robert Levinson disappeared in Iran back in 2007 while working for the CIA. His family said they’re not getting any answers about his whereabouts.

The release of the five Americans, four of them negotiated along with the Iran nuclear deal, did not include Levinson. "It’s devastating news for the family of Bob Levinson," said U.S. Sen Bill Nelson, D-Fla.

The four men released as part of a swap between the countries — Washington Post reporter Jason Rezaian, former U.S. Marine Amir Hekmati, pastor Saeed Abedini and Nosratollah Khosravi-Roodsari — were to be flown to Switzerland, U.S. officials said. The fifth, U.S. student Matthew Trevithick, was released independently of the exchange.

Loved ones took to social media, posting statements on his behalf. "We are happy for the other families. But once again, Bob Levinson has been left behind. We are devastated," read one message.

Another message read, "Cooperating is not enough. Robert Levinson has been left behind. This is not acceptable."

Both messages ended with the hashtag "WhatAboutBob."

Levinson’s son testified on Capitol Hill. He asked for help from Congress and the State Department, but so far, no progress has been made. "When we don’t think of him, how much he must be suffering and what we can do next," he said during his testimony.

Levinson, a retired FBI agent, went missing while on Kish Island, a tourist spot situated between Iran and the United Arab Emirates.

Since then the family has seen a videotape and a few pictures of Levinson. The last proof he was alive was sent in 2011. "Please help me get home," a frail-looking Levinson is heard saying in the video.

Nelson told 7News there is still a possibility that the Iranian government could still assist in tracking Levinson down. "They claim they do not know where he is," he said. "What I would expect is, the Iranian government will double down and make a special effort that, if they do not have Bob in their custody or know about his custody, that they will get out and proactively search to find him."

The FBI is offering a reward of $5 million for information leading to Levinson’s safe recovery.

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