Abu Anas al-Libi, the Al-Qaeda suspect seized in Libya over the 1998 bombings of American embassies in east Africa, is almost unknown in his homeland where he kept a low profile.
The US had been hunting Libi -- real name Nazih Abdul Hamed al-Raghie -- for 13 years for his alleged key role in the deadly attacks on the embassies in Kenya and Tanzania.
With a $5-million (3.7-million-euro) bounty on his head, Libi, 49, was on the FBI's "Most Wanted Terrorists" list.
He was snatched in Tripoli in broad daylight early on Saturday, and the Pentagon said he was being "lawfully detained under the law of war in a secure location" outside Libya.
A source close to Libi said he had returned to Libya at the beginning of the uprising against Moamer Kadhafi in February 2011, battling alongside rebels seeking to topple the dictator.
The married father-of-four lost one of his sons, killed by Kadhafi loyalists during the operation to seize the capital from regime forces in October 2011, the source said.
His family had returned to Libya before him in 2010 as part of an initiative launched by Kadhafi's son Seif al-Islam.
After the uprising, Libi kept a low profile, the relative said.
He had not been working, and only left the house to go to the mosque, dressing in the Afghan style of radical Islamists.
The source said Libi's children had difficulties readjusting to their school in Libya after spending years in exile abroad because of their father.
In 1990, Libi was a member of the Islamist Libyan Islamic Fighting Group, which tried to topple the Kadhafi regime and establish an Islamic state.
After the Kadhafi regime cracked down on Islamists in the early 1990s, Libi fled to Sudan, first joining the Al-Qaeda network, where he climbed the ranks because of his IT and telecommunications expertise.
He also travelled to Afghanistan and Yemen before being granted political asylum in the UK, living in Manchester until 2000.
When a US court indicted him in connection with the 1998 embassy bombings he fled again, finding shelter in Afghanistan and Pakistan.
Ali Soufan, a former FBI agent, said in his book about Al-Qaeda that Libi was "identifiable by a scar on the left side of his face."
Soufan said Libi joined up with Al-Qaeda in Afghanistan "after standout performances at various training camps."
"Apart from his computer skills, he rose to become one of the terrorist group's most efficient operatives and often trained other members," he wrote.
Libi was said to have worked for the Al-Qaeda network in Nairobi in 1993-4.
Libi's group in east Africa had been tasked with scouting out US, British French and Israeli targets in the city, before deciding "the best option was to attack the US Embassy in Nairobi," according to Soufan.
The former FBI agent wrote that Libi's group then travelled to Khartoum to brief Al-Qaeda chief Osama bin Laden.
On August 7 1998, a car bomb explosion outside the American embassy in Nairobi killed 213 people and wounded 5,000.
Almost simultaneously, a truck laden with explosives detonated outside the US mission in Tanzania, killing 11 people and leaving another 70 wounded.
Al-Qaeda claimed responsibility for both attacks.
In September 2012, US broadcaster CNN reported that Libi had been seen in Tripoli.
Western intelligence agencies feared that he had been tasked with forming an Al-Qaeda network in Libya, but had been unable to catch him because of security problems plaguing the country, CNN said.