According to top sources in the Kolkata Police, questions on Mirza's links to Narada CEO Mathew Samuel were asked among others.
Kolkata police has again summoned Mirza and asked him to appear before it tomorrow.
The controversial Narada sting operation, which surfaced ahead of the Assembly elections in the state, purportedly showed several Trinamool Congress leaders and Mirza accepting money for consideration.
West Bengal Chief Minister Mamata Banerjee had on June 17 ordered a probe by the police into the sting operation and asserted that her party had not taken "a single penny" from anyone in the Saradha chit fund scam and the Narada sting operation.
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The next day Kolkata Mayor and Fire and Emergency Services Minister Sovan Chattopadhyay's wife Ratna Chattopadhyay filed a complaint at the New Market Police Station against Samuel.
Samuel was then booked under IPC sections 469 (forgery for purpose of harming reputation), 500 (defamation), 505 (statements conducing to public mischief), 171 (G) (false statement in connection with an election) and 120(B) (criminal conspiracy).
The Kolkata Police had issued the first summon to Samuel on June 23. Four days later, Samuel requested Kolkata Police to withdraw its summon, saying the matter was sub-judice.
An investigation into the Narada sting operation is presently on by the Lok Sabha Ethics Committee, while a case is pending on the issue in the Calcutta High Court.