Rajeev Kumar is facing CBI questioning in connection with the chit fund scam cases in Shillong. (FILE)

Kolkata Police Commissioner Rajeev Kumar is facing questioning in connection with the chit fund scam cases at the CBI office in Shillong today for the fourth consecutive day.

Mr Kumar, who in being examined since Saturday, arrived shortly before 10:30 am at the CBI office in Shillong.

He is being questioned in connection with his role in the alleged tampering of evidence in the Saradha scam, an official told news agency PTI.

Mr Kumar was examined along with former Trinamool Congress MP Kunal Ghosh for the past two days.

The ex-MP was arrested in 2013 in the Saradha scam and has been out on bail since 2016.

The questioning of Mr Ghosh is over for the time being and he was allowed to return to Kolkata, a CBI official said.

The Kolkata Police commissioner had already spent over 24 hours in the past three days inside the highly secured CBI office in Shillong, facing questions relating to Saradha and Rose Valley chit fund scam cases.

The Supreme Court had directed Mr Kumar to appear before the CBI and "faithfully" cooperate in the investigation of cases arising out of the Saradha chit fund scam.

The court chose Shillong as a neutral meeting place "to avoid all unnecessary controversy" and made it clear that Mr Kumar would not be arrested.

The CBI moved the Supreme Court after its officials were thwarted by the Kolkata Police when they had gone to Mr Kumar's official home to question him on February 3.

Chief Minister Mamata Banerjee had rushed to the spot and staged a three-day 'Save the Constitution' sit-in against the CBI move, accusing Prime Minister Narendra Modi and BJP national president Amit Shah of plotting a "coup".