A Birmingham travel agent was involved in a £500 million money laundering scam which saw the proceeds of crime sent to overseas bank accounts.
Liaquat Ali, 44, of Woodlands Road, Sparkhill, was jailed for 12 years after a retrial when he was found guilty of money laundering at branches of Watan Travel.
The Sparkhill-based travel agency, which also had a branch in Bradford, Yorkshire, laundered tens of millions of pounds into the legitimate banking system by bypassing money laundering regulations.
The cash, which was believed to be generated by criminal gangs dealing in drugs, was delivered by couriers to premises in Leeds where it was counted before being taken to various travel agencies.
The decade-long Customs and Revenue inquiry can only now be reported for the first time as the last of the 11-member gang that was behind the scam was convicted at Leeds Crown Court this week.
The investigation centred around the activities of three travel agencies which used the Hawala banking system as a cover for money laundering between 1997-2001.
The Hawala system is used to transfer money, by depositing cash at one location and collecting it at another. The scam was discovered after financial institutions noted suspiciously large transactions by the businesses involved.
Akhtar Hussain, 46, of Keighley, West Yorks, was also jailed for 12 years and Mohsan Khan, 48, of High Wycombe, Bucks, was handed a five-year term after pleading guilty to money laundering offences
David Odd, from HM Customs, said: "Hundreds of thousands of pounds in 'dirty cash' was being ferried up the M1 on an almost daily basis.
"The money was then deposited into business and personal accounts at various banking outlets, converted into foreign currencies and transferred to accounts in the US, United Arab Emirates and across Europe.
"We hope this sends a stark message to those who launder the proceeds of crime that we will bring them to justice."
The Court of Appeal quashed all the gang members' convictions on a point of law in 2005. The judges ordered a retrial, which f inally concluded on Tuesday.
Watan Travel processed more than £333 million through its accounts between 1997 and 2001.
The other travel agents involved were Bradford Travel Centre and Ramzan Travels, based in Halifax.
Officers found cash contaminated with Class A drugs at both Watan Travel and Ramzan Travel. About £2 million was found at Ramzan Travel, in Halifax, including £450,000 stuffed at the bottom of the bed of the firm's owner, Amer Ramzan, who was later jailed for nine years.
Customs officers who raided Bradford Travel Centre found faxes and financial documents showing that payments totalling £3,799,410 were made to bank accounts in Guernsey, Hong Kong and Switzerland.
Mr Odd said: "This result represents the culmination of several years hard work by many HMRC officers.
"This has been a complex case. Having successfully obtained convictions once, we were obliged to do so again."