The group used another vehicle, equipped with a heavy duty boot-liner hidden under a pile of tools, to move around tens of thousands of pounds in criminal cash.
Judge Tim Gittins said: "It was a sophisticated enterprise that preyed upon people's addictions, addictions that often cause misery to them and their lovedones, as well as the wider public through offending caused to fund their addictions and the cost to the public health purse."
Judge Gittins said the gang supplied "industrial quantities of class A and B drugs" on a commercial basis and were "arrogant" in their execution of the illegal trade.
During a 22 week trial, drugs lynchpin John Allcock and his associates denied their roles in the conspiracy, which saw detectives monitor and close in on their underground operation between January 10, 2017 and May 31, 2018.
As a result of the investigation, officers seized more than £120,000 cash, 65 kilos of cannabis and mixing agents, as well as Class A drugs.
During the complex police operation, which was launched by officers from the North East Regional Special Operations Unit (NERSOU), Allcock and his trusted lieutenant Carl McAlindon were monitored as they ran their illicit business, buying and sourcing drugs from members of the North West organised criminal group.
Allcock would regularly travel to Liverpool and Manchester to meet with associates and was observed visiting an industrial unit which the group had access to, suspected to have been used to store large quantities of amphetamine, which he later bought and employed couriers to distribute.
The men attempted to evade detection by conducting shady face-to-face business meetings, as well as via encrypted devices and also used a number of tactics to frustrate police activity.
After a lengthy period of surveillance on the group, officers made their first move and arrested Liverpool-based courier Paul Marrow on September 15, 2017, on the A1 in Durham.
With the assistance of a drugs dog, a hidden electronically operated compartment complete with a trap door was found inside his white van and contained a block of high purity cocaine worth around £180,000.
Two months later, further enquiries saw the recovery of almost £50,000 in cash after a targeted vehicle stop in Lincolnshire.
A search of the van revealed the cash secreted beneath a fixed, heavy-duty boot-liner under a pile of tools.
The takedown of the group continued into 2018 when officers arrested two more couriers, Baber Azim and Glen Stoddart.
Azim was intercepted as he travelled through the Cleveland Police area in possession of cash and a kilo of cocaine.
Stoddart was caught in Swansea having travelled there with £250,000 worth of Cannabis and later collected £21,250 in cash.
Allcock, who was residing in Spain, was later arrested with the help of the National Crime Agency in a final swoop by officers determined to bring the illegal operation to an end.
The entire group were subsequently arrested and charged with a string of drugs and money laundering offences.
John Allcock, 52, of Hillmeadows, Willington, County Durham was found guilty of Conspiracy to Supply Class A and B drugs and money laundering.
Judge Gittins said Allcock had a "leading role" in the conspiracy and told him he had "substantial direct links to those in the supply chain, above and below you".
He sentenced the "career criminal" to a total of 21 years behind bars.
The court heard Allcock's new life in Spain has been "completely lost" now and there are now financial pressures on his family.
He plans to study for a degree in prison.
Carl McAlindon, 37, of Abbey Road, Jarrow, was found guilty of Conspiracy to Supply Class A and B Drugs and money laundering.
Judge Gittins said former window cleaner McAlindon was "hard working and industrious" despite his involvement in the "vile" trade.
He was sentenced to 13 years behind bars.
Bernard Sewell, 41, of Roman Road, Jarrow, was found guilty of Conspiracy to Supply Class B drugs.
The court heard Sewell was a hard working family man with character references and had a more "discreet role" in the conspiracy.
He was sentenced to four-and-a-half years behind bars.
Mark Hiscock, 46, of Cheviot Road, South Shields, was found guilty of money laundering.
He has no relevant previous convictions and a good employment history but Judge Gittins said he was "aware of the scale and nature of the drugs operation" that lay behind the cash he transported.
He was jailed for 12 months and £49,990 recovered from a vehicle he was driving has been seized under the Proceeds of Crime Act.
David McFarlane, 53 of Hadrian Road, Jarrow was found guilty of money laundering.
Judge Gittins said it was clear McFarlane knew the money he transported came from commercial scale supply of drugs.
The judge said McFarlane was "clearly not the brains behind the operation" and was not a key player and sentenced him to 12 months behind bars.
A total of £34,880 which was seized from him has been seized under the Proceeds of Crime Act.
Glen Stoddart, 53, of Mariners Point, Hartlepool, was found guilty of conspiracy to supply Class B drugs, money laundering and participating in activities of an Organised Crime Group.
The court heard he has an offer of employment for when he is released and had a good career before his "fall from grace" led to his involvement in drugs.
Judge Gittins said Stoddart played a "significant role" in the conspiracy and jailed him for five-and-a-half years.
During the trial, two men admitted their guilt.
Paul Marrow, 62, of Rainford Road, Dentons Green, St. Helens, Merseyside, admitted Conspiracy to Supply Class A drugs.
Baber Azim, 43, of Kendridge Road, Slouth, Berkshire, admitted Conspiracy to supply Class A drugs and money laundering.
They will be sentenced separately.