Omar Abdel Rahman, who was convicted of conspiracy in the 1993 World Trade Center bombing and of planning more attacks as part of a "war of urban terrorism" in the US, has died in a North Carolina prison.
Abdel Rahman, 78, was serving a life sentence on several convictions when he died of natural causes on Saturday at a federal prison's medical centre in Butner, North Carolina, the US Bureau of Prisons said.
Abdel Rahman, an Egyptian, was blind, had diabetes and coronary artery disease.
He was jailed at the Federal Correctional Complex in Butner for nearly 10 years.
His family in Egypt received a phone call from a US representative confirming his death, his son Ammar said.
Another of his sons, Abdullah, denied all accusations against his father as he blamed the US for causing his death.
"He was surprised that America was the country that falsely accused and arrested him," Abdullah told Al Jazeera, speaking from Istanbul, Turkey.
"They even became creative in the way they killed him slowly. In the last few days of his life, they took all of his medicine.
"Is this America, the land of freedoms? Look how they treated the man who is old, blind, and ill and who came to America to call for freedom. They took the worst revenge against him, only because he used to say the truth. They conspired with the [former Egyptian President Hosni Mubarak's] regime against him."
Much of the case against Abdel Rahman, a preacher at a New Jersey mosque, and his followers was based on video and audio recordings made with the help of his bodyguard, who became an FBI informant.
One of those videos showed four defendants mixing fertiliser and diesel fuel for bombs.
After a nine-month trial, Abdel Rahman and nine of his followers were found guilty in October 1995 on 48 of 50 charges.
Six people died in the attack and more than 1,000 people were injured in the attack on February 26, 1993.
Abdel Rahman opposed Sadat, left, and was an accused in a plot to kill Mubarak [DH Kennerly/Getty Images]
Abdel Rahman did not testify at his trial, but at a sentencing hearing gave a speech of more than 90 minutes, through a translator, proclaiming his innocence and denouncing the US as an enemy of his Islamic faith.
"I have not committed any crime except telling people about Islam," he said.
Abdel Rahman remained a spiritual leader for some, even after more than 20 years in prison.
With his long grey beard, sunglasses and red and white cap, he was a famous religious figure in the 1980s and 1990s.
His following was tied to killings and bomb attacks around the world.
Abdel Rahman, who was born in a village along the Nile on May 3, 1938, grew up studying a Braille version of the Quran.
As an adult, he was accused of issuing a decree leading to the 1981 assassination of Anwar Sadat, the Egyptian president he had criticised for years.
Abdel Rahman said in Egypt he was hung upside down from the ceiling, beaten with sticks and given electric shocks while held, but he was eventually acquitted and went into self-imposed exile in 1990.
He managed to get to New York after the US embassy in Sudangranted him a tourist visa in 1990 - despite the fact that he was on the state department's list of people with "ties to terror groups".
US authorities blamed a computer error for the visa, but the mistake was compounded in 1991 when Abdel Rahman was given a green card and permanent US resident status.
Abdel Rahman's convictions also included plotting to kill Mubarak during a visit to the US in 1993, a Jewish New York state legislator and a Jewish New York State Supreme Court justice.
Source: Al Jazeera and news agencies