The original report came from CBS last night.

Ayman al-Zawahiri – the second most powerful leader in al Qaeda and Osama Bin Laden’s No. 2 – may be critically wounded and possibly dead, CBS News chief foreign affairs correspondent Lara Logan reports exclusively.

CBS News has obtained a copy of an intercepted letter from sources in Pakistan, which urgently requests a doctor to treat al-Zawahiri. He’s believed to be somewhere in Pakistan’s remote tribal areas of Pakistan.

The letter refers to Sheikh Dr. Ayman al-Zawahiri by name – and says that he is in “severe pain” and his “injuries are infected.”

It is reportedly written by local Taliban leader, Baitullah Mehsud, whose signature and seal are visible on the letter.

The Taliban logo and the Mehsud’s seal have been confirmed by experts as legitimate.

The letter is dated July 29 – one day after a U.S. air strike that killed al Qaeda weapons expert Abu Khabab al-Masri, and five other Arabs in South Waziristan.

U.S. authorities have said they do not have information that al-Zawahiri was present during Monday’s strike, or that he was injured.

However, a counter-intelligence expert and other U.S. officials confirmed to CBS News that the U.S. is looking into reports that al-Zawahiri is dead.

——————————————

Denials of the rumor’s accuracy have since come from a Taliban spokesman, the Pakistani military, and a senior US Counter-Terrorism official.

——————————————

Bill Roggio advises taking the report with a grain of salt.

All of these rumors have been based on Pakistani intelligence sources, which makes the allegations suspect. Without confirmation from the US military or intelligence, the reports from Pakistan should be viewed with deep skepticism. …

This week’s report of a strike that resulted in the death of both Zawahiri and Khabab is identical to the reports emanating from Pakistan in January 2006.