Prosecutors said they believed the gang smuggled heroin, cocaine and cannabis worth up to £7bn into the UK.

Two trials – one lasting for a record 23 months – have previously resulted in the conviction of 18 defendants.

At Manchester Crown Court, Sohail Qureshi and Khaleed Vazeer were respectively jailed for 25 and 20 years. Meanwhile Ghanzanfar Mahmood received a sentence of three years and nine months.

Twelve other members of the gang have already been jailed.

The National Crime Agency (NCA) said the OCG illegally imported drugs more than 240 times from the Netherlands before they were distributed across the UK.

Between 2015 and 2018, the gang smuggled more than 50 tonnes of heroin, cocaine and cannabis.

To conceal their crimes, the OCG set up a series of front companies and warehouses across Greater Manchester, Lancashire, Cheshire and Yorkshire, as well as in the Netherlands.

Drugs were typically transported in consignments of strong-smelling foodstuffs such as onions, garlic and ginger.

In fact, the gang bought so many onions – between 40 and 50 tonnes a week – that it often had to send them back and forth between England and the Netherlands.

During one of the trials, prosecutor Andrew Thomas KC commented: “The stench of criminality is overpowering.”

The court heard Qureshi was a “high level, executive” member of the gang, reporting directly to ringleader Paul Green.

Green, based in Widnes, Cheshire, was jailed for 32 years earlier this month.

Qureshi played a leading role in setting up new supply lines for the gang when they began to suspect a previous plan – involving the setting up of a front company – had been compromised.

Before passing sentence on the latest three gang members, Judge Paul Lawton said “career criminals” Qureshi and Vazeer had been secretly recorded at a London restaurant discussing criminal opportunities and drug smuggling.

The judge said they had helped import drugs on an “industrial and hitherto unprecedented scale”, causing “incalculable” harm across the UK.

“What was actually being imported was misery, social degradation and, in the case of some addicts, death,” he added.Richard Harrison, the NCA’s regional head of investigations, said the gang had “absolutely no ethics”.

He added: “They stooped incredibly low and left a trail of devastation for entirely innocent people by cloning businesses and stealing identities.

“Crime and Policing Minister Dame Diana Johnson said law-enforcement agencies were “determined to bring these organised drug gangs to justice”.

She added that “our streets will be safer with these criminals no longer free to prey on vulnerable people in the name of profit”.

The last of the three convicted gang members will be sentenced at a later date.