Kolkata Police Commissioner Rajeev Kumar cannot be arrested but has to cooperate with the investigations into the ponzi scams in West Bengal, the Supreme Court said on Tuesday, in what both Mamata Banerjee and the Centre claimed as a "moral" victory.

Kumar would have to make himself available before the investigating agency, namely the Central Bureau of Investigation (CBI), and "faithfully" cooperate at all times. To avoid controversy, however, the location has been fixed as the agency's office in Shillong, Meghalaya.

In the contempt plea filed against the chief secretary, DG and police commissioner, a notice has been issued to file their replies on or before February 18. On consideration of the replies, the court may require the personal presence of the officers on February 20, the order said.

Banerjee addressed the media shortly after the directive and said it was a victory of the people, the Constitution and democracy. Her sit-in protest -- "Save India, Save Democracy" -- which started after a showdown between the CBI and Kolkata Police on Sunday evening, has entered the third day. Law Minister and Bharatiya Janata Party (BJP) leader Ravi Shankar Prasad, too, described it as a great moral victory.

Banerjee, who held a press conference shortly after the apex court directive, appeared to be in top spirits and was heard breaking into a patriotic song -- Aye Mere Watan Ke Logon.

On the Supreme Court's clear directive that no coercive steps, including arrest, shall be taken against the commissioner of police, Banerjee said, "We are so obliged.

This will raise the morale of the police force."

Banerjee said that the CBI normally calls people for interrogation, arrests them and takes them to either Odisha and Delhi. In the same breath, she added, "I am not against the CBI as long as they act impartially."

Banerjee's "Save Democracy" platform has become a galvanising force for the anti-BJP front. On Monday, Rashtriya Janata Dal (RJD) leader Tejashwi Yadav and Dravida Munnetra Kazhagam (DMK) leader Kanomozhi joined the dharna to express solidarity. Andhra Pradesh Chief Minister Chandrababu Naidu is expected this evening. Support from leaders of anti-BJP parties has been pouring in from Sunday night.

"We will jointly take a call whether to continue with the dharna," Banerjee said when asked whether it would be called off. "This is a greater platform to save India," she added.

Meanwhile, the state will play host to industry leaders from February 7 at its annual investor show, the Bengal Global Business Summit. The two-day summit will continue till February 8 but the CEOs are expected in the city by Wednesday evening.

What the SC order says

• Rajeev Kumar to appear and make himself available before the investigating agency, namely the CBI
• Rajeev Kumar to faithfully cooperate with the investigating agency at all times
• No coercive steps, including arrest, shall be taken against the commissioner of police
• Commissioner of police to appear before the investigating agency in Shillong on such dates as may be fixed
• Chief secretary, DG of police and commissioner of police to file replies in contempt petition on or before February 18