Via The Telegraph:
He was recommended by a close relative who was trusted by leaders of al Qaeda in the Arabian Peninsula (AQAP), the network's Yemeni wing, according to US intelligence.
His British passport made him attractive as a recruit for a suicide mission as he would be able to board a flight to America under the visa-waiver programme.
But AQAP strategists were persuaded that he was a true believer willing to blow himself up on a plane to the US by what they believed to be his reliable family roots.
The mole, who has been moved with his family to a country outside the Middle East under Western intelligence protection, was reportedly born in the region, but grew up Europe and had British citizenship.