This article has the details. It's not a French-bashing article; it appears the French and the Brits were working together on the case. However, the details of the British handling of teenage asylum-seekers (a.k.a., "children") is somewhat alarming:

London plays host to 3,700 unaccompanied children, who are automatically put into social services care and provided either with foster homes, a place in a children's home or put up in B&B and rented accommodation.

The apartment where the ricin was found was rented to two such "children."

The first article also mentions that the Algerians are believed to have undergone "training programmes" in Afghanistan, the remote Pankisi Gorge region of Georgia and Chechnya, all of which have an al Queda connection. However, the link to Iraq that some want to draw remains to be discovered.