A city-based terror suspect, arrested on April 1 at the Petrapole border, had reportedly played a key role in facilitating the Mumbai blasts in July 2006.

Sheikh Sameer, who had set up base in Jorasanko in May 2006, had helped his friend Zahibuddin Ansari, alias Zaby, enter India from Bangladesh with explosives that were used in the blasts.

This was revealed during a narco-analysis test on Sameer, the report of which recently reached the CID.

Sleuths said Sameer, who worked for the Lashkar-e-Toiba, was also linked to the prime suspect in the Hyderabad blast, Mohammad Andul Sahed, alias Bilal.

“The narco report has thrown up several key details about Sameer and his network. It has also shed light on his associates in Calcutta,” said Rajeev Kumar, deputy inspector-general (operations), CID.

Zaby was a “close friend” of Sameer since his days in Aurangabad. Mumbai police stumbled upon his name for the first time when their anti-terror squad seized a huge cache of arms in May last year.

“The report of the narco-analysis test will help both Hyderabad and Mumbai police,” said a CID officer. “Since a bulk of the explosives was routed through Calcutta, it becomes even more important for us to grill Sameer in detail.”