The information came from the interrogation of Rashid Rauf, a Briton whose arrest by Pakistani agents in early August allegedly led to the uncovering of the conspiracy to bomb US-bound planes, they said. The officials, speaking on condition of anonymity, did not identify the militant but said he was on the level below the terror network's chief Osama bin Laden and deputy Ayman al-Zawahiri.
"His area of operations is in Kunar," one of the senior officials told AFP. The official said their information about his whereabouts was based on information provided by Rauf and added that "coalition partners" had been informed.
When asked if the US-led forces stationed in Afghanistan were chasing the individual, the Pakistani official said: "Obviously we are working very closely, and co-operation among the coalition partners is excellent." He would not divulge if there had been any progress in the hunt.
Afghanistan, which has quarrelled with its "war on terror" ally for months over militancy along their rugged and porous border, said Pakistan was trying to shift the blame. "As we've said in the past, we believe that information coming from the Pakistani intelligence services is diversionary," said Daud Muradiaan, a senior advisor in the Afghan foreign ministry.
"We in Afghanistan believe that Afghanistan is no longer a safe haven for al Qaeda. As a result of ours and the international community's efforts, Afghanistan dosn't remain a safe haven for al Qaeda."
But Pakistani officials say that Rauf used members of a militant group Jamaatul Furqan-blamed for a 2002 attack on an Islamabad church-as a conduit to communicate with the al Qaeda operative.
Islamabad confirmed last week the arrest of two Britons and five Pakistani "facilitators" but has identified only Rauf. Security sources told AFP on Friday that Rauf's father Abdul had also been detained in recent days. Rashid Rauf was communicating with the Kunar-based al Qaeda contact, the official said but did not explain whether the communication was through human messengers or by phone.
Al Qaeda leaders including bin Laden are said by Pakistani officials to frequently use couriers to avoid sophisticated electronic surveillance by Pakistani and US security agencies.
Mountainous, forested Kunar borders Pakistani tribal areas where US and Afghan officials have said they believe bin Laden and his henchmen are most likely hiding.