Abdelbeset Ali Mohmed al Megrahi, the only person convicted in connection with the Lockerbie bombing that killed 270 people, died Sunday, the Libyan government and a family member said. He was 60.
The former intelligence officer, who had suffered from prostate cancer, will be buried Monday, a foreign ministry spokesman said.
Al Megrahi's cousin Omer al-Gharyani told CNN he was with al Megrahi at the Tripoli hospital when he died.
His death came more than two years after he was freed from a life sentence in Scotland on the grounds that he was dying.
The destruction of Pan Am Flight 103 over Lockerbie, Scotland, in 1988 in the deadliest act of air terrorism against Americans until the September 11, 2001attacks on New York and Washington, according to the FBI.
American and British investigators who painstakingly pieced together the wreckage of the Pan Am 103 found it had been destroyed by a bomb, and they accused al Megrahi and another man of planting it.
Al Megrahi -- once the security chief for Libyan Arab Airlines -- and Al Amin Khalifa Fhimah were Libyan intelligence agents, the United States and Britain charged, indicting them in November 1991 on 270 counts of murder and conspiracy to murder.
The indictment set off the first of two international battles over al Megrahi. The first resulted in international sanctions and finally led to his trial and conviction.
The second came after he was released from a Scottish prison, on the grounds that he was diagnosed with terminal prostate cancer in August 2009 and was expected to have only a few months to live. He was sent home to Libya on "compassionate" grounds, and received a hero's welcome at the airport.
His release -- a little more than eight years after being sentenced to life in prison -- and the celebrations that greeted him in Libya sparked condemnation from the U.S. and British governments and some victims' families.
The fury grew as he lived long past the time doctors had expected him to survive. U.S. senators including Robert Menedez and Frank Lautenberg, both New Jersey Democrats, and Charles Schumer, a Democrat from New York, called for an investigation into why he was set free.
"This man was a horrible man," Schumer said Sunday in an interview with CNN. "It would have been better had he not died in freedom, but died in prison. That's what he deserved, and i still believe that the Scottish government, perhaps with the participation of the British government, created a major injustice when they let him out."
"The only legacy we have is in the memory of all those who were lost," Schumer added. "...We have to just make sure we continue this battle against terrorism on airplanes. We made great progress and we have to keep it up."
Al Megrahi's death may make it impossible ever to get the full story behind the Lockerbie bombing.
In an interview with Reuters last October, al Megrahi said the truth will come out "one day, and hopefully in the near future." He vowed that "new facts" would come to light.
Al Megrahi always insisted he was innocent, and filed one appeal after another against his conviction. The first was rejected in 2002.