A published report says information recovered from safe houses when al-Qaida's leader in Iraq was killed in June places the group's leadership in Pakistan's border region.
The Washington Post newspaper said Monday a member of Osama bin Laden's high command revealed the Waziristan location in a letter written last December to al-Qaida-in-Iraq leader Abu Musab al-Zarqawi.
The letter was signed by "Atiyah," a person counter-terrorism officials believe is Atiyah Abd al-Rahman, who joined bin Laden during the 1980s.
In the letter, the writer said he was with the al-Qaida high command in the Waziristan region of Pakistan.
If accurate, the letter would confirm the location of the al-Qaida leadership, at least at the time it was written.
U.S. intelligence officials have long believed the al-Qaida leadership is hiding in one of the tribal provinces in Pakistan near the Afghan border.
The Washington Post says the letter warned Zarqawi that he risked being removed as al-Qaida's leader in Iraq if he continued to alienate Sunni Muslim tribal and religious leaders and rival insurgent groups.
Zarqawi was killed in June when U.S. warplanes bombed his hideout in a village north of Baghdad.
Some information for this report was provided by Reuters.