Confirmation of the meeting came during interrogations carried out by Pakistani intelligence agents. The arrests in Pakistan took place between August 9 and August 11, a senior Pakistani official familiar with the investigations said.
Pakistani officials have refused to name the al Qaeda suspect. But senior Pakistani officials have said in private that evidence linking the alleged London plotters to an al Qaeda leader based in Afghanistan would prove their argument that the plan was being directed by an Afghanistan based al Qaeda cell.
"The evidence pieced together so far suggests that at least one, and possibly two, meetings took place in southern Afghanistan – most probably somewhere around Kandahar," said the senior Pakistani official, who spoke on the condition of anonymity. "We have now established that the information was passed on from al Qaeda to these people, face-to-face during these meetings," he added.
Pakistani intelligence officials are believed to have concluded that the al Qaeda suspect – who one senior intelligence official said is "among the hierarchy which works one step below Osama bin Laden and Ayman Al Zawahiri" – is a member of an al Qaeda special cell, whose members are hiding on the outskirts of Kandahar.
Pakistani officials have described this cell as one which is dedicated to developing previously unknown ways of using explosives.
"Their main task is simply to make certain that explosives can be successfully taken through checkpoints at airports, train stations and other transportation links," said another senior intelligence official who also spoke on the condition of anonymity.
Suspects arrested in the U.K. in connection with the alleged plot to target a number of commercial airliners leaving London's Heathrow Airport for destinations in the U.S. are being investigated for planning to use different kinds of apparently harmless liquids which mixed together could produce deadly explosives.
Pakistani officials are keen to refute speculation that the planners of the attack had close links to the south Asian country as most of those arrested in the U.K. are of Pakistani origin. Additionally, Rashid Rauf, a 25 year old U.K. national of Pakistani origin who migrated with his parents when he was less than one year old, has been arrested in Pakistan in connection with the case.
In a related development, western diplomats based in Islamabad said, they believed, Matiur Rehman, a leading militant and a key leader of the 'Lashkar-e-Jhangavi' – a Pakistani militant group banned by president General Pervez Musharraf – may be in custody of Pakistani security services.
One diplomat said the Pakistanis may delay confirming his arrest till further interrogations are carried out.
"Once his arrest is confirmed, maybe some of his accomplices in the field would go on the run. I think we may see some more arrests of people linked to this guy before we know for sure, he is with Pakistani intel," said one senior western diplomat who also asked not to be named.