The District Court also imposed fines of PLN 30,000 zloty (EUR 7,092) on each defendant, along with PLN 4,000 (EUR 946) payments to charity.
Both sides have indicated they may appeal the verdict.
The men, aged between 42 and 50, were caught red-handed in autumn 2024 when officers from Poland's Central Investigation Bureau of Police (CBŚP) raided a property in the village of Orla in the Podlaskie region.
Three were arrested at the scene; a fourth was caught after a brief chase.
Around 600 litres of liquid methamphetamine were found – enough, according to a court-appointed expert, to produce approximately 800kg of of the drug in crystalline form.
Prosecutors had sought sentences of 15 to 17 years and argued the lab was supplying one of the Mexican cartels.
The defence requested acquittal on some charges and lighter overall sentences.
The court convicted the men of large-scale drug production and membership of an organised criminal group, though it stopped short of finding any of them guilty of leading it.
Only one defendant admitted guilt; two claimed they had been coerced into travelling to Poland and working at the lab.
Presiding judge Marzenna Roleder said the men had been recruited in Mexico and had their travel paid for.
They rented a warehouse in Białystok and later a house in Orla – both arrangements made entirely online – and purchased the necessary chemicals through a mix of physical and online transactions.
"The defendants flew all the way from Mexico to Poland to produce drugs here. That cannot be tolerated – hence the very severe sentence," the judge said.
(ał)
Source: PAP