BBC News with Marion Marshall

British security officials say the crucial tip-off on the parcel bombs addressed to a Chicago synagogue and discovered on cargo planes on Friday came from a suspected al-Qaeda member. The man is a Saudi Arabian national. More from our security correspondent Gordon Corera.

It appears that a member of al-Qaeda who had been to the Saudi rehabilitation programme, then left and went and joined al-Qaeda in the Arabian Peninsula in Yemen, but then left again and left the al-Qaeda grouping and returned to the Saudi authorities. About two weeks ago, we think, and with him came a tip-off and the intelligence about this potential plot which was then shared by the Saudis with American and other authorities, and clearly that was vital because if these devices had got through the initial security screening, and so without that tip-off, they may well have exploded.