A CBI source on Saturday told IANS that Kumar, a 1989 batch IPS officer, considered close to West Bengal Chief Minister Mamata Banerjee, may be arrested in the case if he does not respond to the CBI's summons.

The source said that Kumar had headed a probe by a Special Investigation Team related to both Saradha and Rose valley ponzi scams prior to the CBI taking up the case in 2014 on Supreme Court's orders.

The SIT was set up by Chief Minister Mamata Banerjee in 2013 after the multi billion rupee Saradha scam came to light, when the Saradha group's companies downed shutters across Bengal, unable to pay back the depositors.

The group had raised huge money, mainly from poor people who, lured by the promise of huge returns, parked their life's savings with the firm.

The federal agency, now probing the ponzi scam caes, needs documents related to the investigation from Kumar.

Kumar's last public appearance was on Thursday when he attended the inauguration of the International Kolkata Book Fair in Kolkata where Banerjee was also present.

Kumar was also seen at the stall put up by the city police, where the chief minister unveiled a number of books.

However, Kumar had stayed away from a scheduled meeting with the visiting full bench of the Election Commission on Thursday.

Taking umbrage, the Election Commission on Friday said it has sought an explanation about his absence from the state home secretary, Kumar's reporting boss.

Hours later on Friday, Banerjee said Kumar was on leave, and apologised to the election panel for his absence.

The CBI had last month arrested Bengali film producer Shrikant Mohta for his connection with Rose Valley chit fund case.