A fraudster who stole £20m ($27m) in a fake green carbon scheme that targeted celebrities and spent it on luxury properties in Dubai has had his prison term increased by 10 years. Scientist Michael Richards, who was behind one of the UK's largest tax frauds, has now had his 11-year sentence lengthened after failing to repay £11.1m. He, along with four other fraudsters, told investors their money would be spent on research and development into carbon credits, attracting more than £65 million in investment in the ‘green’ scheme. However, only £16 million of this was spent on planting trees. Instead, the group stole £20 million of the investors’ money and laundered it via bank accounts and secret trusts, and spent it on luxury properties in London, Australia and Dubai. As well as buying property in Dubai, Richards also spent £32,000 on a diamond engagement ring for his girlfriend from luxury London jewellers Boodles. The group also failed to pay around £6.5million in tax. Richards, described as the ringleader, convinced super-rich investors the group was running cutting-edge research and development projects in Brazil and China, and assured his celebrity clients they would be eligible for tax relief and encouraged them to make claims to HMRC for a total of £107.92m. The fraud ran between 2004 to 2010. Richards, 59, was originally convicted and sentenced in 2017 of cheating the public revenue and disqualified from being a company director. At his hearing, Mr Justice Edis described the businessmen's conduct as "utter dishonesty and astonishing greed hidden behind a mask of concern for the environment". The Crime Prosecution Service's (CPS) Proceeds of Crime Division successfully applied to the court for Richards to repay £9,999,999 of the stolen money in 2019, this has now risen to £11.1 million due to interest. But due to him only returning £30,000, the CPS took him to Westminster Magistrates’ Court for non-payment of the full amount and requested an additional prison sentence be activated instead. “Michael Richards failed to pay back the £11 million he owed the public so the CPS had to take him back to court and now he’s had 10 years added onto his current sentence," Adrian Foster, Head of the CPS Proceeds of Crime Division, said. “We worked with Her Majesty's Revenue and Customs (HMRC) to make sure he did not benefit from the proceeds of his crime, but he has only paid back a paltry amount. “Even when fraudsters are convicted and sentenced the CPS will continue to pursue them for the money they owe, or they risk remaining in prison for many more years.” Another fraudster in the scheme, Evdoros Demetriou, 82, a former senior executive at EMI and Warner Music, had nine years added onto his six-year prison sentence in July, after failing to pay back £4.6 million. In total, all five offenders were told to repay £20.6 million. Robert Gold was sentenced to 11 years' imprisonment and disqualified from being a company director. Barrister Rodney Whiston-Dew, a former president of the Rotary Club of London, was jailed for 10 years and Eton-educated Jonathan Anwyl was sentenced to five-and-a-half years' imprisonment. Last year, the CPS recovered more than £100 million from criminals from their proceeds of crime. Gill Hilton, assistant director of HMRC's Fraud Investigation Service, said the men were behind one of the UK's biggest tax frauds. “Richards was convicted of one of the UK’s biggest tax frauds and owed the taxpayer almost £10 million," she said. “At the confiscation hearing in 2019 the judge gave him a choice of paying the money or facing another decade in prison. After only paying back £30,000, he now faces the consequences. “This outcome is a warning to anyone involved in tax fraud. Our work doesn’t stop at conviction and together with our partner agencies we will pursue the proceeds of crime."