One couple told the BBC’s consumer affairs programme Rip Off Britain that they have been forced to sell their “dream home” in the UK because Harlequin will not return their investment, despite failing to build the agreed overseas property.

Since investing, the husband has developed cancer and is no longer able to work, leaving his wife “frightened” for the future without the “cushion” the promised return their nest egg was supposed to provide by investment in Harlequin.

The unregulated Harlequin scheme worked by taking deposits from mainly UK investors to build off-plan properties in the Caribbean, which could then be sold at a profit on completion or used to generate a rental income from holidaymakers.

But out of a scheduled 6,000 properties, only around 300 have actually been built.

The programme, which aired on 6 January, showed that at least one family managed to get back their deposit, once they found out about extended delays to the building of the property they had invested in, but only after Rip Off Britain first reported on their case in 2010, five years after they had invested in a property Harlequin told them it would only take two years to complete.

Later investors have not been so lucky.

They have been told by Harlequin that, since the company entered liquidation last October, it can not return their deposits, despite a clause in one couple’s contract saying that if the property had not been built by the end of June last year they would be entitled to a full refund.

Harlequin chairman David Ames has told them their best hope of seeing any of they money back is by joining a controversial investment trust to hold Harlequin’s remaining assets, orchestrated by him.

But the investors Rip Off Britain spoke to have said they won’t sign up to it, because it “ties their hands behind their back” by preventing them from taking any legal action against Harlequin or Ames for five years.

Ames told the programme the investors had “misunderstood” the trust, and that clauses in it to prevent legal action are there to protect its funding and “allow a better chance of financial success”.

But the Harlequin chairman said it will not be until the middle of this year until the financial position of the company is “any clearer”.

He blamed the problems at Harlequin on the “global recession, contractor fraud, defamatory campaigns and new FCA [Financial Conduct Authority] regulations”.

However the Serious Fraud Office and Essex Police have had an open and ongoing investigation into dealings at Harlequin since 2013.

The then regulator the Financial Services Authority issued a warning to advisers about the company in January 2013, and a further warning to investors in June of that year.