(CNN)Here's a look at Robert Levinson, who went missing in Iran in 2007.
Birth date: March 10, 1948
Birth place: Flushing, New York
Birth name: Robert Alan Levinson
Father: name unavailable publicly
Mother: name unavailable publicly
Marriage: Christine (Gorman) Levinson
Children: Douglas, Samantha, David, Daniel, Sarah, Stephanie, Susan
Education: Attended New York University; City College of New York, B.A., 1970
During his career at the FBI, Levinson specialized in investigating organized crime in Russia.
His family says Levinson suffers from diabetes and high blood pressure among other illnesses.
1970s - Levinson is hired by the FBI after six years with the Drug Enforcement Agency.
1998 - Levinson retires from the FBI.
1998-2007 - Levinson works as a private investigator.
2006 - Levinson is hired as a contractor by Tim Sampson, head of the Illicit Finance Group within the Office of Transnational Issues at the CIA, to write reports for the agency. The contract is for approximately $85,000. Three CIA employees, including Sampson, later lose their jobs for overstepping their authority as analysts and withholding information about Levinson after he disappeared.
March 8-9, 2007 - According to State Department officials, Levinson travels to Kish Island in Iran and checks into a hotel. Reportedly, Levinson is in the Middle East to investigate cigarette smuggling on behalf of a client. During the visit, he meets with American fugitive Dawud Salahuddin, who is the last person to acknowledge seeing him on March 9.
June 1, 2007 - US President George W. Bush says he is "disturbed" by Iran's refusal to provide any information on Levinson. "I call on Iran's leaders to tell us what they know about his whereabouts."
December 2007 - Levinson's wife, Christine Levinson, meets with government officials in Iran, but does not learn anything about her husband's disappearance.
2008 - The CIA pays the Levinson family more than $2 million to head off a lawsuit, according to family attorney David McGee.
March 3, 2011 - US Secretary of State Hillary Clinton says that evidence is growing that Levinson is alive and being held somewhere in southwest Asia.
December 2011 - The Levinson family publicly releases a "proof of life" video they received in November 2010. In the video, Levinson says, "I have been treated well, 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."
March 6, 2012 - The FBI offers a $1 million reward for information leading to his safe return.
September 2012 - Christine Levinson attempts to meet with Iranian President Mahmoud Ahmadinejad during the UN General Assembly in New York. He does not meet with her but tells CNN, "They told me (Levinson) was in Iran, and of course the question came up in my mind, what was an American intelligence officer doing in Iran...an individual is lost, how are we supposed to find him among 7 billion people spread across the globe? What we can do is assist, help and cooperate, which we have been doing, and we are doing... as a humanitarian gesture and action."
January 2013 - The Levinson family releases a series of photographs they received in April 2011. In the photos, a bearded, shackled Levinson, wearing an orange jumpsuit, holds signs written in broken English.
September 2013 - CNN's Christiane Amanpour interviews Iranian President Hassan Rouhani. When asked about Levinson, Rouhani says, "First, you mentioned a person that I've never heard of. Mr. Levinson, we don't know where he is, who he is. Sometimes you are speaking of people who come before a court of trial and other times, there are people who disappear. It's not a clear question to put these two categories side by side. He is an American who has disappeared. We have no news of him. We do not know where he is. We are willing to help and all the intelligence services in the region can come together to gather information about him to find his whereabouts. And we're willing to cooperate on that."
September 27, 2013 - US President Barack Obama speaks by phone with Iranian President Rouhani. One of the topics discussed is Levinson.
December 12, 2013 - The Associated Press and The Washington Post report that Levinson was working for the CIA when he disappeared in 2007, possibly investigating corruption among Iranian officials. The AP says it first learned of Levinson's CIA ties in 2010 but delayed publishing the information at the government's request. The next day the New York Times reports it has known of Levinson's CIA work since 2007 but also delayed publishing the information to avoid jeopardizing his safety.
December 13, 2013 - White House Spokesman Jay Carney says Levinson "was not a US government employee when he went missing in Iran."
December 15, 2013 - US Secretary of State John Kerry says, "Well, there hasn't been progress in the sense that we don't have him (Levinson) back. But to suggest that we've abandoned him or anybody has abandoned him is simply incorrect and not helpful. The fact is that I have personally raised the issue, not only at the highest level that I have been involved with, but also through other intermediaries."
December 2013 - Salahuddin, the last person to acknowledge seeing Levinson, tells the Christian Science Monitor that both he and Levinson were detained by Iranian police on March 9, 2007. "They took me away, and when I left - we were down in the lobby - Levinson was surrounded by four Iranian police."
January 21, 2014 - In an interview with CNN, Levinson's family discloses that they have known for some time that he was working for the CIA. They accuse the US government of failing to do enough to find Levinson.
January 22, 2014 - Iranian Minister of Foreign Affairs Mohammad Javad Zarif tells CNN's Jim Sciutto, "I have not seen anything that could prove that he (Levinson) was ever in Iran. In fact, we have seen evidence ... he was last seen alive outside Iran, with pictures showing that he was outside Iran when he was last seen. It's a very unfortunate case. We've said clearly that we have no knowledge of his whereabouts... We need the United States to explain for Iran what a CIA operative was doing, if he was ever in Iranian territory, what was he doing in Iranian territory."
March 9, 2015 - The FBI increases the reward for information on Levinson to $5 million.
January 20 2016 - FBI investigators believe Levinson, if he is still alive, is being held in Iran despite public statements from US officials in other agencies indicating he may be elsewhere, according to US officials briefed on the investigation. Three days earlier, on January 17, Iran had released four Americans in a prisoner swap, but not Levinson. After the swap, US President Obama says that Iran has agreed to "deepen our coordination" in trying to locate the still-missing American.
February 11, 2016 - The Senate passes a resolution recognizing that Levinson is the longest held US civilian in US history and urging Iran to "act on its promises to assist in" his case.
March 21, 2017 - Levinson's family files a suit against Iran with the US District Court in Washington, DC. They are filing suit under the Foreign Sovereign Immunities Act "for injuries suffered by each of them as a result of Iran's unlawful acts of hostage taking, torture and other torts."
November 4, 2019 - The Department of State Rewards for Justice (RFJ) Program announces a reward of up to $20 million for information leading to the safe return of Levinson, in addition to the FBI's previously announced reward of $5 million.
November 8, 2019 - The UN Working Group on Enforced or Involuntary Disappearances says Iran's Justice Department has acknowledged there is an "an on going case in the Public Prosecution and Revolutionary Court of Tehran" for Levinson, according to a joint statement from Levinson's family that was provided to CNN. Levinson's family had asked the UN working group to investigate his 2007 disappearance in Iran, and hopes that the report constitutes the first acknowledgment from the Iranians that Levinson is in the Islamic Republic.
March 9, 2020 - On the 13th anniversary of Levinson's abduction, the FBI renews its "repeated calls to Iran to uphold its prior commitments to cooperate and to share information which could lead to Bob's return. To date, the leadership of the government of Iran has fallen far short of any such commitments."
March 25, 2020 - The family of Levinson announces that they believe he is dead. "We recently received information from U.S. officials that has led both them and us to conclude that our wonderful husband and father died while in Iranian custody. We don't know when or how he died, only that it was prior to the COVID-19 pandemic," they said in a statement.
December 14, 2020 - Senior US government officials say they have identified and sanctioned two senior Iranian intelligence officials who were involved in the abduction and "probable death" of Levinson.