Five other members of the gang, which cold-called members of the public using high pressure sales tactics to persuade them to purchase shares in a company that owned land on the island of Madeira, have already been given jail sentences. Nascimento was described as the controlling mind, instigator and the main beneficiary of the fraud.

Over 170 individuals invested more than £2.8m in the shares, on the suggestion these would rise in value once planning permission was given to build 20 villas. Many were elderly or vulnerable, and lost life-changing sums, in some cases all their life savings.

Investors were promised guaranteed returns of between 125% and 228%. None were ever paid. Investors’ money was used to maintain the fraud and particularly to fund Nascimento’s lifestyle, Southwark Crown court was told.

Mark Steward, executive director of enforcement and market oversight at the FCA, said: ‘This brings to an end the FCA’s largest fraud prosecution which has seen the perpetrators imprisoned for a total of 28.5 years, affording justice to victims who were the subject of their calculated deception. We are continuing to fight for compensation for victims out of their assets.'

In sentencing Nascimento, the judge remarked that he had shown 'utter cynicism and contempt' for some of the victims. He said that some of the stories he had heard during the trial were 'positively heart-breaking' and that many of the victims had suffered 'life-shattering losses'.

The judge commented that Nascimento was 'very adept at getting others to do his dirty work for [him]' and that many of his actions were 'specifically designed to frustrate the task of the FCA and to prevent apprehension' but nonetheless 'the FCA had built a formidable case' against him.

The FCA said that whilst every effort has been made to identify and contact investors who purchased shares in either Pearl Island International (later known as Paragon Private Wealth) or Berkeley Brookes (later known as Atlantic Equity) the FCA would like to hear from anyone who purchased shares in these companies who has not already heard from the regulator.

They are advised to contact the FCA through the consumer helpline on 0800 111 6768 or by completing and online reporting form, quoting 'Operation Tidworth'.

Nascimento also received an additional sentence of two years for further criminality in respect of a separate prosecution by the Crown Prosecution Service and the City of London Police. This makes his total sentence 13 years.

Charanjit Sandhu, one of the members of the team previously convicted, has received an additional consecutive sentence of 3.5 years in relation to matters prosecuted separately by the Crown Prosecution Service, City of London Police and Kent Police. Taking account of the 5.5 years sentence passed for involvement in the boiler room operation, this makes his total sentence nine years’ imprisonment.

The additional sentences for both men related to conspiracy to defraud and money laundering offences. They miss-sold carbon credits to unsuspecting victims through two companies, Harman Royce Ltd and Kendrick Zale Ltd.

Report by Pat Sweet