(CNN) -- The wife of a retired FBI agent who disappeared in Iran nearly five years ago said Friday that the family received a video of her husband being held hostage a "little more than a year ago" and has only now released it publicly in an attempt to prompt his release.
The video features nearly a minute of Robert Levinson, appearing gaunt and pleading for help. His family has posted the video on its website, www.helpboblevinson.com, along with two minutes of video of his wife, Christine, and his son, David, asking his captors for guidance on how they can help bring about his release.
"We feel that this is a way to try and reach them with our plea and the video to them to let us know what the family needs to do to get Bob home, alive and quickly," Christine Levinson told CNN.
She said it was "very sad to see him looking the way he does."
She said the family had tried to communicate with the captors when they received the video, which Secretary of State Hillary Clinton alluded to in March, when she said the United States had received "recent indications" that the 63-year-old Coral Gables, Florida, man was being held in southwest Asia.
Also in March, a U.S. government official and a senior diplomatic official said the United States had received proof that Levinson was alive.
At least one e-mail sent to Levinson's relatives by his captors is believed to have originated from an Internet cafe in Pakistan or Afghanistan, a U.S. government official told CNN on Friday.
At least two meetings involving Iran and the United States took place, said the official, who declined to be identified because of the sensitivities surrounding the case. It was unclear who may have attended the meetings, or how or when they may have occurred. Such meetings would be unusual, given that the two countries have no diplomatic relations.
The discussions, not equivalent to negotiations, were described as "working-level," meaning they were not conducted by senior administration officials, the official said.
White House Press Secretary Jay Carney said Friday that the U.S. government was doing what it could. "We have worked on his case since he disappeared and we will continue to do so until he is reunited with his family," he told reporters.
U.S. Senator Bill Nelson, D-Florida, said the U.S. government "has pulled out all stops to help," he told CNN.
Since Levinson disappeared, the U.S. government has said repeatedly that it hopes Iran would provide help to find out what happened to Levinson who was last seen on Iran's Kish island in 2007. Levinson's wife and son also travelled to Iran seeking information about him.
Levinson was last reported seen on Iran's Kish Island in March 2007. In the video, he said he had been held for three-and-a-half years.
His appearance marked the first publicly known evidence that he was alive. He wore a white shirt and spoke seated in front of a gray wall. Middle Eastern-style music played in the background.
He said he wasn't in very good health and was running "very quickly" out of diabetes medication.
"I have been treated well," Levinson said in the video. "But I need the help of the United States government to answer the requests of the group that has held me for three-and-a-half years. And please help me get home. Thirty-three years of service to the United States deserves something. Please help me."
State Department spokeswoman Victoria Nuland said Friday the FBI is the lead agency in the case, and investigators have been "working intensively" on it.
Nuland said it was the family's decision to release the video.
Speaking in the video on behalf of his family, David Levinson thanked the captors "for taking care of my father and for continuing to provide him with the care, the medical treatment he needs to stay alive."
His father, who also has high blood pressure, looks healthy in the video, and that "was a comfort to the family," David Levinson said.
David Levinson asked the captors to pass along their demands "so we can work together" to bring his father home.
"We are not part of any government and we are not experts on the region," he said. "No one can help us but you. Please help us. We tried to contact you, but you never responded," he said. "I am sending this message because we need to know what you want our family to do so that my father can come home safely."
David Levinson said his father has seven children and two grandchildren.
On the website message, Christine Levinson, wearing a headscarf, said to her husband: "I will continue to do everything I can to bring you home alive.
"All I want is for our family to be whole again. We love you. We miss you every day. We will not abandon you."
The former FBI agent-turned-security consultant was last heard from on March 8, 2007, when he checked into a Kish Island hotel. He had planned to return to the United States the next day.
Levinson's family said in 2010 that he was working as a private investigator in Dubai and may have been looking into a cigarette-smuggling case.
He was not working for the U.S. government when he disappeared, said the State Department, which has pressed Tehran for information about his whereabouts.
Iranian authorities have said they do not know what may have happened to him. Christine Levinson told CNN that President Mahmoud Ahmadinejad said in September that "he was willing to help find Bob and send him home to us. I'm hoping that he will continue to do that."
CNN previously reported that, shortly before he disappeared, Levinson had met with Dawud Salahuddin, an American fugitive who lives in Iran.
Salahuddin, known in Iran as Hassan Abdulrahman, told CNN in a 2007 interview that he was given refugee status in Iran after admitting that he had killed Ali Akbar Tabatabai, who had been a diplomat under the shah. Tabatabai was killed in Maryland in 1980.
Salahuddin was detained by Iranian officials in plainclothes and taken to be interrogated about his Iranian passport in 2007, he said in the interview. When he was freed the next day, he said, he was told by officials that Levinson had returned to Dubai.
His story matches accounts from friends of Levinson. They say Levinson feared he would be arrested after meeting with Salahuddin.
In December 2007, Levinson's wife and other family members met with government officials in Iran. Christine Levinson has said they were polite, but provided no details regarding her husband's whereabouts.
A year later, she flew to the United Nations to ask Ahmadinejad about her husband, but the Iranian president declined to meet her.
Robert Levinson retired from the FBI in 1997 and was not involved in intelligence matters with the bureau, officials have said. He became a principal at Business Integrity International, which describes itself as an investigative/security consulting firm.
CNN's Ed Hornick, Jennifer Rizzo, Susan Candiotti and Elise Labott contributed to this report.