Six members of a crime group have been jailed for a total of 45 years for a £107.9 million, eco-investment tax scam believed to be one of the UK’s biggest tax crimes.

They were given sentences totalling 45 years for devising a fake eco-investment scheme based on false carbon credits as a tax break for wealthy investors.

HMRC says the case was the latest of a string of operations to tackle “serious multi-million pound frauds by wealthy professionals”.

HM Revenue and Customs investigators stopped a group of bankers, businessmen, a solicitor and an engineer from cashing-in on what they thought was the “perfect crime,” says HMRC.

The men, led by Cambridge-educated engineer Michael Richards, 55, from East Sussex, lured wealthy individuals to invest in largely fake environmental projects with the promise of a tax break. An intensive forensic investigation lasting 10 years revealed the scheme was “nothing more than a fraud based on a complex series of contrived bank and paper transactions.”

The group used the investors’ money to fund lavish lifestyles, buying properties around the world, expensive jewellery and enjoying luxury holidays.

Simon York, director of Fraud Investigation Service at HMRC said: “This was an audacious and cynical fraud on an astonishing scale, characterised by greed and a complete disregard for the ecological causes the perpetrators claimed to be supporting. Instead the group spent investors’ money on their own lavish lifestyles.

“These individuals thought they had worked out the perfect fraud. At every step they used contrived offshore structures, complex transactions and blatant lies in an attempt to hide their tracks and derail our criminal investigation.

“But the determination and professionalism of our teams has shown, yet again, that we will not hesitate to bring fraudsters to justice. Work has now begun to recover the proceeds of this crime in order to fund vital public services.”

Mr Richards, the self-styled ringmaster and originator of the fraud, led the group to create and trade Carbon Emission Reduction Certificates which help countries hit environmental emissions targets set by the United Nations. He was sentenced to 11 years in prison.

He was assisted by entrepreneur Robert Gold, 49, of Dubai, described in court as Richards’ “bulldog and negotiator” who ensured the fraudulent deals took place. He was sentenced to 11 years in prison.

Rodney Whiston-Dew, 66, from south-east London - a solicitor and former president of the Rotary Club of London - set up the complex offshore structures to disguise the true nature of the fraud and hide the money, none of which was declared to HMRC. He was sentenced to 10 years in prison.

The other group members found guilty at Southwark Crown Court were ‘environmentalist’ and business consultant Jonathan Anwyl, 44, of East Sussex, who received a five and a half year sentence, and former music industry executive and ex-banker Evdoros Chrysanthos Demetriou 78, from Oxford, who received six years.

They denied charges of conspiracy to cheat the public revenue when the case opened in February 2017 at Southwark Crown Court. Mssrs Richards, Gold, Whiston-Dew and Demetriou also denied cheating the public revenue. But they were found guilty by a jury and sentenced on Friday 10 November, 2017.

Another of the group, Malcolm Gold, 73, previously of Hertfordshire, pleaded guilty to a charge of cheating the public revenue in November 2016 and was sentenced to 20 months in prison in January 2017.

Sentencing the men, His Honour Mr Justice Andrew Edis said: “You played with high stakes and lost. It was bare-faced dishonesty and you did everything to inflict loss on the public, the people who pay their taxes, who were also victims.

“It was utter dishonesty, sophisticated planning and astonishing greed hidden behind a mask of concern for the environment.”

There is no evidence to suggest investors – who are paying back the money they received from HMRC - knew the scheme was a scam or that their money was not being spent on research and development.

HMRC is seeking to recover criminal proceeds from the fraudsters.