Eight CBI officials had come to question Kolkata police chief Rajeev Kumar in connection with two Ponzi schemes.
Several hundred Kolkata police personnel surrounded the CBI’s offices in the city and forcibly took the officials to a nearby police station.
“They came to the commissioner of police’s home without any court order or warrant. The matter is sub judice in the Kolkata High Court and there is a stay order. This is blatantly wrong and an infringement on our federal structure,” she said.
"There is total constitutional breakdown. It is my job to protect my officers," the chief minister said on Sunday evening. "They [the BJP] cannot fight is politically. That's why they are resorting to all this."
Banerjee then launched a sit-in protest, known as a dharna, in central Kolkata accompanied by police chief Rajeev Kumar. The protest entered its second day on Tuesday.
"This is a Satyagraha and I'll continue till the country is saved," Banerjee said, citing the form of protest developed by Mahatma Gandhi.
Several leaders of the Indian opposition have voiced their support for Banerjee over the incident, including Congress chief Rahul Gandhi and Rashtriya Janata Dal chief Tejashwi Yadav.
The CBI has announced that it will move the Supreme Court to initiative contempt of court proceedings against Rajeev Kumar for obstructing an investigation into chit fund scams.