BJP, the ruling party of India, questions West Bengal Chief Minister (CM) Mamata Banerjee's sit-in protest which started after Kolkata police chief Rajeev Kumar was taken to a police station and was detained there for hours for questioning by the Central Bureau of Investigation (CBI) before he was released yesterday, reports NDTV.

CBI was investigating into two chit fund scams allegedly involving members of Mamata's Trinamool Congress party.

"Is Mamata Banerjee trying to protect herself? Why is she running way from the inquiry," asked Union Minister Prakash Javadekar.

Meanwhile, Mamata Banerjee accused the centre of sending CBI officers after "one of the best officers in the world, someone who's integrity, bravery and honesty are unquestioned", NDTV reports.

Rajeev Kumar had headed a special probe into the Saradha and Rose Valley chit fund scams in which thousands of small investors were cheated of their money.

The CBI says that he had ignored multiple summons over the past two years and that the agency wanted to ask him about missing evidence.

"Is it to hide evidence, the chit fund scamster in his testimony said there is one red diary. There is a diary and a pendrive," Prakash Javadekar said. Those are missing, says the government, as a witness talked about turning them over but the police never included them on the evidence list.

The senior BJP leader also pointed out that it was not his party but Rahul Gandhi's Congress that had filed a petition in the Supreme Court asking for an investigation into the chit fund scams. The constitutional mechanism, he said, had clearly failed. Mr Javadekar hit back to Mamata Banerjee's calling the situation in Kolkata an "emergency" saying, "This is not Narendra Modi''s emergency but Mamata Banerjee's emergency in Bengal. She is on a dharna to save herself from the CBI."

"Why a chief minister was protesting for a police chief. The fact that paramilitary forces had to be deployed for the protection of (CBI) officers, who were diligently doing their duty, is for the first time an unprecedented view given to the citizen with regards to the state of anarchy in the West Bengal," said the Union Minister Smriti Irani, NDTV reports.

The BJP also took potshots at Rahul Gandhi for his tweet expressing support for Mamata Banerjee last evening. "Diagnosed: Multiple Personality Disorder is characterized by at least two distinct and enduring personality states - there is trouble remembering certain events, beyond ordinary forgetfulness. These states alternately show in person's behavior. Get well soon, Rahul ji," the BJP tweeted.