British law enforcers have teamed up with police in the Persian Gulf to track the assets of a Midlands millionaire exposed as one of the UK’s most prolific fraudsters.

They said they were amazed to find his life in the millionaire’s playground of Dubai was even more ostentatious than his rock star UK lifestyle.

Craig Johnson, from Staffordshire, was jailed for 12 years after masterminding a £138million fraud.

His ill-gotten gains brought him a life of luxury, including a mansion in Staffordshire, yacht and helicopter, and a fleet of luxury cars.

He was ordered to repay £26million to the taxpayer, but recovery specialists have so far only managed to claw back £6million.

But a team working in Dubai found details of an even more luxurious second lifestyle as they looked into Johnson’s empire in the Gulf emirate.

In a landmark investigation, HM Revenue & Customs officers with police in the UAE unravelled Johnson’s life, and were surprised to discover the extent of his dealings.

He owned a string of luxury properties and boasted of owning a major car dealership selling high-end motors to the super-rich.

He spent millions setting up a rally team in 2002, and entered the Middle East Rally Championship twice. But workers who went out from the UK to join Protrak World Motorsport found themselves abandoned in Dubai after he was arrested in the UK. The team disbanded and most of the staff found their way back to Britain.

Euan Stewart, criminal investigations director with HMRC said: “It is fair to say, as extravagant a lifestyle as Johnson lived in the UK, we believe the lifestyle he lived in Dubai was as extravagant, if not more so.”

Investigations are continuing in all the parts of Johnson’s business empire.

An associate of Johnson said: “He had private jets and helicopters and whatnot and there are not many ex-pats who have that. Back then, four or five years ago, it was a smaller community, and the big fish seemed even bigger.”

He added few people had any idea about Johnson’s background, and even after he was jailed, there were not many who knew what had happened to him.

The joint UK-UAE investigation was one of the first times the two countries have worked together, coming shortly after the two countries signed an extradition agreement.

In June 2006, Johnson was one of seven men imprisoned after an eight-month case at Birmingham Crown Court. His multi-million scam led to a five-year inquiry by customs officials.

He had been part of a gang importing and exporting mobile phones between companies, with VAT kept illegally every time phones were moved. The profits were filtered through a series of bank accounts and business transactions.

The phones were allegedly imported VAT-free from EU countries. But in many instances the phones did notexist. The paperwork showed they had been sold on cheaply, with VAT added, through a chain of companies known as “buffers”. The firm that ‘paid’ VAT would then claim it back from the Government, while the company that owed it disappeared. In November that year, Wolverhampton Crown Court ordered the fraudster to pay back £26million.