Kolkata, July 11 (IANS): The Enforcement Directorate (ED) on Saturday grilled Rose Valley group chairman Gautam Kundu at Presidency Jail, where he is now lodged after his arrest around three and-a-half months back.

ED sources termed the interrgoation as routine.

"This was a routine investigation and was carried out as planned," a source told IANS but refused to give any more details about the grilling.

"Questioning is done to get more information and was done accordingly," the sources said.

Kundu was arrested on March 25 by the ED after he failed to give proper answers during sustained questioning spread over several hours on being summoned to its office.

The investigating agency has already filed a charge sheet against six officials of Rose Valley including Kundu under provisions of the Prevention of Money Laundering Act in pursuance of a complaint from the Securities and Exchange Board of India (SEBI).

The ongoing investigation on the Kolkata-based ponzi firm has revealed that it had garnered more than Rs.15,000 crore from public through issue of various financial instruments which did not have sanction of the capital market regulator.

Found guilty of running "collective investment scheme" without necessary approvals, the SEBI in June 2014 had ordered the company to refund the money to the investors and barred it from accessing the securities market.