A land banking business shut down by the Insolvency Service last year convinced investors to hand over £10m in less than three years.
Century Property Group was closed down on 18 August 2011 and was last week ordered into liquidation in the High Court on grounds of public interest.
While the original investigation found 225 plots of land had been mis-sold to the public on at least ten separate sites, raising more than £2.6m, the Insolvency Service said it has since discovered three more sites, bringing the total to about £10m.
The business, which operated from the Tower 42 building in the City of London, persuaded one family to invest £600,000.
Company investigations supervisor Chris Mayhew said: "Unscrupulous land banking companies who target vulnerable people, especially through cold calling, and persuade them to invest in land at exaggerated prices are peddling the myth of easy money and ruining lives.
"I would urge anyone who receives a call from an unknown source asking them to part with money or information to question it, take time to reflect and seek independent advice."
The Insolvency Service has now taken public interest winding-up action against more than 60 land banking companies which have between them have raised £40m from investors.
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