As Mamata Banerjee government took on the Central Bureau of Investigation on Sunday, the family members of CBI personnel became an unwitting casualty. For three hours, 13-year-old daughter and wife of Joint Director of Kolkata CBI Pankaj Srivastav cowered at their residence as 50-60 state police men surrounded the house and banged on the door continuously.

"My family is scared. They are fear for my security. I think the state police will break down the door any moment and arrest me," Srivastav told CNN News18 minutes before Mamata Banerjee announced her sit-in protest against CBI's move to question Kolkata police commissioner Rajeev Kumar in connection with chit fund scam.

CBI's interim director Nageshwar Rao rejected Banerjee's charges and alleged the CBI officers were being targeted to destroy evidence in the Saradha and Rose Valley cases. "I don't know under what sections my men have been arrested/ detained. My fear is CBI complex at both salt lake and Nizam palace will be attacked to destroy evidence," Nageshwar Rao told CNN News18. Rao added that allegations of CBI acting at the behest of a political party were baseless.

"We are only following the law and the rule book. We are not politicians but investigators. Rajiv Kumar was not cooperating so we had to resort to these steps," he told CNN News18.

As West Bengal police gheraoed CBI officials, SOS calls went out to prime minister's office in Delhi. "I have informed my director in-charge. Central government must intervene. If we can’t investigate in Supreme Court monitored case, how are we going to do our jobs?” Pankaj Srivastav told CNN-News18.

Nageshwar Rao said law officers of CBI are looking into the matter. There is a possibility that the CBI might approach the Supreme Court on an urgent basis to break the impasse. Senior officials said that the possibility of sending CRPF to rescue Srivastav’s family and other personnel was considered but a final decision is awaited. Law and order is a state subject and sending in central paramilitary forces without consent of state government could lead to another constitutional crises.