Egyptian doctor Ayman al-Zawahiri, credited with being the brains behind the extremist network, became as head of Al-Qaeda when Bin Laden was killed by US troops three years ago.
James Ujaama, 48, told the trial of British hate preacher Abu Hamza that he fell ill with a "very bad cold" while in Kabul in late 2000, a year before the September 11 attacks on New York and Washington
"He gave me some honey and black seed," Ujaama told the Manhattan court where Abu Hamza is on trial for 11 kidnapping and terror charges. "He was very caring."
Ujaama worked for Abu Hamza between 2000 and 2001, running the website of the cleric's "Supporters of Sharia" organisation based in London.
Also Read
He was jailed for six years in the United States on a terror conviction and has an agreement with the government requiring him to testify against Abu Hamza.
Later that year, he traveled to Afghanistan via Pakistan, tasked by Abu Hamza with accompanying British recruit Feroz Abbasi, and doling out thousands of dollars to a girls' school.
But Ujaama said he left Abbasi behind in Pakistan and travelled alone into Afghanistan after securing safe passage from the Taliban's then-foreign minister.
He took 2,500 British pounds to a girls' school in the city of Khost and 1,500 pounds split between three individuals, who included an explosives expert who had cared for Abu Hamza.
Ujaama said he also installed computer software on Taliban computers in Kandahar.
He then oversaw the delivery by courier to Kabul of 6,000 British pounds, computers for the girls' school, and jewelry for widows and children of mujahideen fighters, all sent by Abu Hamza, he said.