The CBI scanned the call log details of the two mobile phones used by Sheikh. According to the documents available with the authorities, Sheikh had made 28 phone calls from the two mobile phones in a span of 30 minutes before the attack on January 5.

Based on the call log details of the two phones, the CBI officials have prepared a list of names of those who were in contact with Sheikh and have summoned them. Nearly a dozen people from Sandeshkhali area have been summoned for interrogation at Nizam Palace including some panchayat level leaders, say sources.

On Monday, the CBI arrested three persons in connection with the case. It took into custody Jiauddin Molla, panchayat pradhan of the Sarberia Agarpara gram panchayat, Sheikh’s security guard Didar Baksh Molla and another person Faruk Akunji.

According to officials, all three are close associates of Sheikh, who is considered the mastermind behind the attack. These were the first arrests in connection with assault on the ED team.

The Calcutta High Court on March 5 had ordered the transfer of the probe into the January 5 attack as well as Sheikh’s custody, from CID to CBI. The West Bengal government had challenged the High Court order in the Supreme Court. But the Supreme Court last week on Wednesday refused both – the urgent listing of the matter as well as stay on the Calcutta High Court order.

The apex court, in its verdict, upheld the HC decision on the CBI investigation and questioned the state government why it took them 50 days to arrest Sheikh. The Bengal police arrested Sheikh on February 29, who was on the run for 55 days since the attack.