On Friday, Detective Department chief Jawed Shamim visited Alipore Central Jail and grilled him for hours.

The police feel that he may provide leads to the Indian Mujaheedin module which provided logistical support to the Mumbai attackers — including procuring SIM cards.

While Shamim refused comment on the issue, a senior officer of Kolkata police said: “The same IM module bought the SIM cards. Ansari could provide us with vital clues since he was part of the group led by Amir Reza Khan from the early days.”

The Mumbai police had recently arrested Indian Mujahideen operative Mohammed Saddik Israr Ahmed Shaikh, for his alleged role in the serial bomb blasts this year. Saddik was also allegedly one of the attackers in the American Center shootout. Amir Reza Khan, another top leader of Indian Mujahideen, was involved in the plot too.

Currently, the Special Task force and CID are investigating 37 SIM cards being used by terrorists in Pakistan and J&K. Some were, in fact, transported to Karachi from Kashmir. Three of these were found in possession of terrorists who attacked Mumbai.

“The cards were bought two months ago from Kolkata and suburbs by Bengal-based Indian Mujahideen modules,” said a senior officer of Kolkata police. An STF team has gone to J&K to find out who purchased the SIMs.

The top cops, however, weretightlipped.

“We conducted raids, but nothing substantial has so far come to our knowledge,” said Siddhinath Gupta, DIG, CID (Special Operations Group).

On Thursday night, raids were conducted in Santoshpur Bazar in South 24-Parganas, Beniapukur and Premantle Street in Kolkata and Bashirhat in North 24-Parganas.

A couple owning a cell phone shop in Santoshpur Bazar and another from Premantle Street are being interrogated.

The owner of the shop in Santoshpur Bazar has reportedly said the persons who bought the SIM cards had given forged voters identity card. He, however, could provide a description of the man who bought the cards and a sketch has been drawn.

Raids were also conducted to nab one Huseinur Rehman, a resident of Nayadandi in Basirhat, who bought a majority of the SIM cards from Kolkata and the suburbs. A Madrasa teacher, Huseinur is absonding.