A police probe into the gang began in May 2020, when intelligence was received that an organised crime group based in Sheffield and Rotherham was operating a nationwide, multi-million pound cocaine and heroin trafficking network using encrypted phones.
Torick Akram, aged 38, of Thorpe Hesley, Rotherham, was the first man to be arrested after a search of his car led to the discovery two suitcases which contained £1.1 million in cash.
Akram was also in possession of an encrypted device, and when officers searched his home, a further £161,000 in cash was concealed in the basement.
The house also contained cash counting machines, elastic bands and cash wrappings.
He admitted to being involved in the counting and processing of cash on behalf of the crime group, effectively operating as their banker, and was sentenced to four and a half years in prison in March 2021.
In June 2020, Joshua Walshaw, 26, of Central Avenue, East Dene, Rotherham, was arrested on the M1 near Wakefield, and found to be in possession of £150,000 in his vehicle.
The investigation found Walshaw worked as a courier for the gang, delivering cocaine and heroin to customers around the country, and collecting payment.
Between March and June 2020, Walshaw delivered 32.25kg of cocaine and 3kg of heroin and collected £651,660 in cash on behalf of the gang.
The two men who led the criminal operation, Adrees Rehman, 27, of Oxley Grove, Broom, Rotherham and Imran Mohammed, 36, of Godard Hall Road, Fir Vale, Sheffield, were also arrested in June 2020, and later charged with conspiracy to supply class A drugs and conspiracy to money launder.
They both had in their possession encrypted phone devices which revealed during the investigation that over a 44-day period between March and May 2020 the gang had supplied 176kg of cocaine and 18kg of heroin.
Over a 74-day period between March and June 2020, they had collected in excess of £6.4 million in cash from the proceeds of their drug supply operation.
The final trio arrested for their involvement in the gang was Michael Moore, 40 and Sarah Jo Fisher, 33, both of Washington Avenue, Wombwell, Barnsley, who worked together as couriers for the gang.
Analysis of their phones found messages which revealed they had been responsible for 21 criminal exchanges and they had collected more than £2.8 million in cash on behalf of the gang.
Christopher Lait, 38, of Hillcote Drive, Fulwood, Sheffield, was also a courier for the gang, carrying out 19 criminal exchanges in which he had collected over £970,000 in cash.
All six appeared at Leeds Crown Court on Friday to be sentenced for their roles in the gang.
The two ringleaders, Mohammed and Rehmah, were jailed for 16 years and 14 years and four months respectively.
Three of the couriers were jailed, with Walshaw locked up for six years and Moore and Fisher both jailed for 20 months.
Lait was handed a 12 month sentence suspended for 18 months.