A leading al-Qaeda militant in Saudi custody reportedly provided the information that helped thwart last week's mail bomb plot.
According to Yemeni security officials, Jabir al-Fayfi, a Saudi militant who had joined al-Qaeda in Yemen but handed himself over in late September, told Saudi officials about the plan.
U.S. officials confirm an alert from Saudi Arabia led to the interception of two explosive devices on two UPS cargo planes. The information was specific enough that it identified the tracking numbers of the packages.
It is still not clear how Saudi Arabia obtained the specific tracking numbers. Al-Fayfi surrendered to Saudi authorities before the packages were mailed and would not likely have known the numbers.
Al-Fayfi had been captured by U.S. forces in Afghanistan in 2001. He was held at Guantanamo Bay until 2007, when he was released to Saudi Arabia.
He was put through the Saudi rehabilitation program for militants. But it apparently didn't work -- shortly after his release, he went to neighboring Yemen and joined al-Qaeda there. In September he turned himself in, and was taken back to Saudi Arabia.
However, Yemeni security officials said they suspect the Saudis planted al-Fayfi in al-Qaeda in Yemen as a double agent and he never really "turned himself in."
Saudi Arabia has been working to infiltrate al-Qaeda in neighboring Yemen for years now. Saudi intelligence has recruited hundreds of informers in Yemen, gives powerful tribal chiefs generous stipends to ensure their loyalty and even passes out money within Yemen's security forces.