A top al-Qaeda leader in Afghanistan, Abu Laith al-Libi was on America's most-wanted list and had a $200,000 (£100,000) bounty on his head.
Libi was regarded as one of Osama bin Laden's lieutenants
Libi, which means "the Libyan" in Arabic, was a mouthpiece for al-Qaeda and is believed to have been a training camp leader.
He was also seen as a key link between al-Qaeda and the Taliban.
He has appeared in a number of al-Qaeda videos, including one with al-Qaeda's second-in-command Ayman al-Zawahri.
He is thought to have been one of al-Qaeda's most senior field commanders in Afghanistan, and to have directed a number of recent suicide bomb attacks in the east of the country.
The US says Libi was behind a suicide bombing in February 2007 which killed 23 people at the American base at Bagram during a visit by US Vice President Dick Cheney.
In October, the US military in Afghanistan named Libi as one of a dozen "mid-level" al-Qaeda and Taleban being sought.
He was the first spokesman on behalf of al-Qaeda to announce that Osama bin Laden and Taleban leader Mullah Omar had survived the US invasion of Afghanistan.
Last year, Major Chris Belcher, a spokesman for the US-led coalition in Afghanistan, said Libi was a guerrilla fighter "knowledgeable about how to conduct suicide bombing missions and how to inflict the most civilian casualties".
He had probably directed "one or more terror training camps," he added.
Born in Libya around 1967, he was linked to the Fighting Islamic Group in Libya (FIGL), an organisation set up with the aim of overthrowing Libyan leader Muammar Gaddafi.
In November, a recording was released claiming the group was becoming part of al-Qaeda.
The tape was attributed to Zawahri and featured a leader of the FIGL introduced as Abu Laith al-Libi.
Described as a "veteran jihadist", Libi was solidly built, 1m 92cm (6'4") tall with dark hair and eyes, and scars on his back.
Islamist web sites have carried messages from him, including one in May in which he said al-Qaeda in Afghanistan was willing to exchange prisoners with Britain and other Western countries.
He was also identified as the bearded man in a video interview who accused Shia Muslims of fighting alongside US forces in Iraq, and claimed mujahideen would crush foreign troops in Afghanistan.