Two Lancashire men are among 10 criminals punished for their roles in a complex fraud targeting cash strapped public bodies and ripping off taxpayers.
It was described as an audacious "high-stakes" criminal conspiracy which defrauded NHS hospitals, councils and the Guernsey government out of £12.6 million, and funnelled cash overseas.
The organised crime network targeted 22 mostly public bodies in a divert fraud, with the dirty money transferred to international accounts and laundered into legitimate businesses.
Businessman Imitiaz Khoda, 44, of Dallas Road, Lancaster, was jailed for 54 months for money laundering, while father-of-seven Oghogho Ehanire, 42, of Brackenbury Road, Preston, was jailed for 12 months suspended for two years for laundering and was given 210 hours of unpaid work.
The scheme had the potential to have siphoned off £20m into the criminals' accounts mainly at the taxpayers' expense.
But the schemers were rumbled when a Lincoln-based NHS hospital raised the alarm, sparking a probe by detectives from Lincolnshire Police which led them to uncover a "seamless process" of fraud and money laundering spanning the UK, but Europe, Africa and the Middle East.
Sentencing Khoda, Ehanire and eight others at Leicester Crown Court, Judge Philip Head said: "This was a sophisticated and widespread fraud in its conception and execution."
He added: "These bodies were selected because it was hoped their accounting processes would be vulnerable."
"The loss falls necessarily on those who are not able to pay it, ultimately the members of the public whose taxes fund these bodies."
The case can only now be reported after reporting restrictions were lifted.
Cash was extracted by fooling organisations with forged letters pretending to be from legitimate building firms already carrying out work for the public bodies.
The fraudsters took advantage of the fact public sector contracts were freely available to see, under financial transparency rules.
The co-conspirators would send correspondence complete with company logos, false signatories and reference numbers - either by email or fax - claiming to have changed their companies' banking details, and supply instead an account controlled by the criminals.
Several of those convicted for their part provided the accounts used, or administered how the money was moved, while others took a leading role in targeting organisations.
Ill-gotten gains were then laundered through "many layers" of accounts and funnelled to legitimate businesses, including a children's soft play area in Scotland and a cafe in Sutton Coldfield, West Midlands.
The conspiracy's tendrils stretched to company accounts in Poland, Dubai and Nigeria, with targets including an airport development run by the States of Guernsey, the Royal College of Arts (RCA), and NHS trusts in Lincolnshire, London, and the North.
The conspiracy's "trusted lieutenant" Stephen Tyndale, 47, of Albany Road, Southwark, London, was jailed for 10 years, for conspiracy to defraud and conspiracy to launder money.
Asif Habib, 53, of Al Barsha, Dubai, Abdul Naeem, 36, of Lineholt Close, Redditch, Worcestershire, and his brother Mohammed Nadeem, 33, also of Redditch, were convicted of conspiring to launder the dirty cash.
Habib was jailed for 40 months, and the brothers for 67 months each.
Given suspended jail terms for laundering were Yagnesh Patel, 46, of Rookery Road, Staines, Surrey; 15 months, Zaheed Muhammed, 48, of Tinto Road, Glasgow; 21 months, and Abdul Ghaffar, 68, of Lineholt Close, Redditch; 22 weeks.
Tariq Khan, 35, of Meadway, Ilford, Essex, was jailed for eight months and ordered to repay £20,000 to the Lincolnshire NHS trust after admitting perverting the course of justice by supplying false documents to police.
Monica Thomson, 40, of Ivy Way, Airdrie, North Lanarkshire, will be sentenced for her part in the conspiracy next month.
In one case, a £1.28 million payment to build a mental health unit at Lincoln's St George's Hospital site was diverted, after NHS trust staff failed to check the new bank details supplied.
It was only when an employee of the building firm Costain saw the bogus letter, with its logo out of place, a fake reference number and dodgy signatures, that the alarm was raised.
The Guernsey government, and taxpayers, lost £2.6 million to the fraud.
Judge Head added: "Over 18 months, 21 bodies were contacted.
"Some made checks and ignored the fraudulent communications.
"Some did not, and made such payments."
He also concluded Plymouth University, was targeted, although no money was taken.
Det Sgt Mike Billam, who led the investigation, said: "I am pleased to say that with the assistance of law enforcement in Dubai, Poland and other countries, this investigation has got to the heart of this conspiracy and has disabled what was clearly an international organised crime group."
"The sentences handed out to 10 defendants reflect the fact that these individuals, motivated only by their own personal greed, have sought to take the taxpayers' money."
John Woodhatch, then 56, and Adrian Taylor, 44, were previously jailed for a total of 11 years at Southwark Crown Court in September 2015, for money laundering and acquiring criminal property.
The "prime-mover", identified in court as Nigerian national Bayo Awonorin, is still at large, having failed to answer to police bail.