The gang - led by Kamaran Khader from Greenock and including Glasgow man Sirwan Hassan from Pollokshields - imported millions of low grade cigarettes, which they sold across northern England and Scotland.
Once in the UK, the goods were transported to storage sites in Blackburn, Oldham, Essex, Ascot and Slough and then distributed.
But the gang was snared after leaving fingerprints and DNA on discarded cans and bottles at sites where they had been operating.
Ringleader Khader, 31, of Greenock's Roxburgh Street, was jailed for six years for his role in planning the criminal operation, sourcing the cigarettes and tobacco and arranging its delivery.
He appeared at Manchester Crown Court on Thursday and Friday along side Sirwan Hassan, 36, of Maxwell Grove in Glasgow.
Hassan was sentenced to five years.
Five other men were also imprisoned for their part in the smuggling ring by His Honour Judge Mansell QC.
The trial heard that the group came to the attention of HMRC in 2010 after officers found 390,000 cigarettes inside a transit van and a further 780,000 cigarettes hidden between sheets of insulation at an address in Blackburn.
The gang were also linked to a seizure of 840,000 Jin Ling cigarettes in September 2011 in Oldham and a shipment of nine million Golden Eagle cigarettes which arrived in Southampton in April 2012.
HMRC officers began to track the gang and on one occasion followed them to a storage unit where they discovered a further 1.4m illegal cigarettes and a plastic carrier bag containing £84,400 in cash.
In January 2013 HMRC officers intercepted a van containing 270,000 cigarettes at an industrial unit in Ascot and in January 2013 they found 1.8m duty free cigarettes at a site in Slough.
HMRC say the smuggling conspiracy totalled £28m.
Jo Tyler, assistant director of criminal investigation for HMRC, said: "These men were making substantial criminal profits at the expense of the taxpayer and, by feeding the black market, were depriving honest retailers of the chance to earn a living.
"But, they were lazy when it came to clearing up after themselves, leaving evidence behind that proved their involvement in this crime."