The Supreme Court on Tuesday ordered Kolkata Police commissioner Rajeev Kumar to "faithfully" cooperate with the CBI in Saradha chit fund case.
The top court said the Kolkata police chief cannot be arrested but he has to make available all evidence to the CBI.
The apex court said Kumar will appear before the Central Bureau of Investigation (CBI) for investigation at Shillong in Meghalaya.
A bench headed by Chief Justice of India (CJI) Ranjan Gogoi also issued a notice to Kumar and sought his response before February 20, the next date of hearing on the allegations by the CBI that he was tampering with electronic evidence and that the SIT headed by him provided the agency with doctored materials.
The apex court also directed the West Bengal chief secretary, the director general of police (DGP) and the Kolkata Police commissioner to file replies on the contempt pleas filed against them by the CBI on or before February 18.
The bench also comprising justices Deepak Gupta and Sanjeev Khanna said on consideration of replies of the chief secretary, the DGP and the Kolkata police commissioner, the court might prefer the personal appearance of these three authorities on February 20.
The bench said the apex court's secretary general will inform them on February 19 whether they are required to be present before the apex court on February 20.
West Bengal Chief Minister Mamata Banerjee called the Supreme Court order a "victory of democracy".
Senior advocate Abhishek Manu Singhvi, appearing for Kumar alleged that the CBI's action was meant to score points.
The applications, accusing the Kolkata Police chief of destroying evidence related to the case, has alleged that an extraordinary situation has arisen in which top police officials of the West Bengal Police are sitting on a dharna along with a political party in Kolkata.
West Bengal Chief Minister Mamata Banerjee has been sitting on a dharna since Sunday.
On Monday she described her sit-in over the CBI's attempt to question Kolkata Police chief as a "non-political" protest.
(With inputs from PTI)