PARIS: French secret service documents relating to the surveillance of Toulouse killer Mohamed Merah have been declassified and handed over to judges investigating his claimed links to Al-Qaeda.

The documents, which were released Friday on the orders of Interior Minister Manuel Valls, are expected to shed light on whether France's internal security agency, the DCRI, blundered in failing to identify Merah as a serious threat to public security in the lead-up to his March shooting spree.

Merah killed three Jewish school-children, a rabbi and three paratroopers in a wave of killings, before being killed himself on March 22 following a 32-hour police siege of his flat in the southern city of Toulouse.

It subsequently emerged that the 23-year-old had been known to the DCRI and had been questioned by agents in November 2011 following his return from a trip Pakistan.

In conversation with police during the siege that ended in his death, Merah claimed he had been in Pakistan offering his services to Al-Qaeda.

But at the time of his November 2011 interview, the security services apparently concluded that he did not represent a significant threat.