Undercover officers watched as Damian Masalski, 25, met Roman Lada, 53, at Birchanger Green service station on the M11 near Bishop’s Stortford, Hertfordshire on January 15 last year.
Masalski passed money to Lada, who then stashed it in his lorry, Luton Crown Court heard.
The next day, Lada tried to leave the UK but was stopped at Dover.
Border Force officers searched Lada’s HGV and found close to £500,000 hidden in the cabin.
Two weeks later, Masalski met Tomasz Dimitruk-Kot, 25, and Damian Mysliwiec, 36, in Stevenage.
When the trio exchanged plastic bags, detectives from a joint National Crime Agency and Metropolitan Police unit pounced, seizing 12kilos of cocaine worth £960,000 at street level and £85,000 in cash.
A search of Masalski’s home in Stevenage uncovered a further £134,450, plus 24 kilos of high quality MDMA worth £962,000.
The search also uncovered written notes referencing the supply of a further 67 kilos of cocaine, potentially worth £5.3 million.
Armed officers stopped Adam Anchim, 36, in Fountains Road, Luton, after an investigation identified him as a criminal associate of Masalski.
In Anchim’s vehicle, officers recovered a handgun, 24 rounds of ammunition, 220 MDMA tablets and 126 grams of cocaine.
At his home was a kilo of cannabis, 423 grams of amphetamine, plus £26,233 and Euros 4,801 in cash.
A probe by the Organised Crime Partnership found that Masalski, Lada, Dmitruk-Kot and Mysliwiec had been working together to arrange for the importation of cocaine into the UK, and that Anchim was linked to Masalski.
Last month, Lada was found guilty of attempting to remove criminal property. He was sentenced to three years and four months in jail.
The other men were sentenced on March 22.
Masalski pleaded guilty to conspiracy to supplying Class A and B drugs and was sentenced to 18 years in prison.
Dmitruk-Kot pleaded guilty to conspiracy to supply cocaine, and received 12 years six months in prison.
Mysliwiec admitted the same offence, plus involvement in other offences and was sentenced to eight years and seven months.
Anchim pleaded guilty to possessing a firearm and possession with intent to supply Class A drugs and was sentenced to seven-and-a-half years.
The combined sentence for all five men is 49 years 11 months.
Detective Inspector Richard Smith, from the Organised Crime Partnership, said: “These five men were involved in a significant criminal operation that brought Class A drugs into our country for profit.
“The additional element of Anchim’s firearm makes their plot even more dangerous.
“Drugs, cash and violence all go hand-in-hand.
“The NCA and Met will continue to work together to stop organised criminals profiting on the importation and supply of drugs, which in turn will help reduce violent crime across London and the rest of the UK.”