Calcutta, Feb. 10: Thousands of investors from across the state and beyond were lured into the latest Ponzi scheme busted last evening with the arrest of alleged kingpin Sanjiv Kapur.

Sanjiv, his brother Rajiv and four associates arrested by Calcutta Police yesterday were today remanded in police custody till February 21. The police are now on the trail of half-a-dozen stockbrokers who were suspected to be linked to the scheme.

Ponzi schemes — which essentially rob Peter to pay Paul — are named after Charles Ponzi, an American who raised millions of dollars in deposits in the 1920s by promising a phenomenal return and defrauded thousands of investors.

Such schemes usually stay afloat as long as their operators can attract investors in large numbers and deposits exceed withdrawals. But they run into rough weather once the funds start drying up.

Sanjiv’s latest scheme offered investors a return of as much as 5 per cent per month on deposits.

The police said Sanjiv operated his racket out of plush offices in Park Circus, Tollygunge and Jadavpur, recruited 30-odd agents to raise deposits and issued newspaper advertisements inviting public deposits.

“Invest Rs 1 lakh in share trading and earn Rs 5,000 per month. Profit guaranteed — loss, if any, will be borne by us,” the advertisements claimed.

Sanjiv had been held on charges of fraud a couple of years ago and spent three months in custody for ripping off investors through a Ponzi scheme that offered an even better return of 10 per cent a month.

Last time, Sanjiv managed to be in business for over two years, spreading out his operation over several firms, so that if one ran into trouble, he could merely close it down without having to abandon the business altogether, the police said.

Investigators moved in fast this time, but thousands had already bitten the high-return bait. “He must have been in business for (the last) three to four months. That’s not too long, yet he appears to have made significant headway into the districts and beyond. We have already traced investors from Uttar Pradesh and Bihar,” an officer said.

Sanjiv had also altered his modus operandi, using some stockbrokers to raise deposits. Among those arrested was a stockbroker — a member of the National Stock Exchange — who allegedly provided Kapur access to the bourses, a police source said.