Officers from the UK Border Agency have raided a chicken processing plant in Lancashire and detained six men suspected of working illegally.
The men from Afghanistan, Pakistan and India were working at halal poultry specialists Gafoor Poultry Products in Preston.
The men, aged between 24 and 32, were arrested on suspicion of illegal entry to the UK, working in breach of visa conditions and overstaying their visas.
Management at the plant will now have to show that all the correct right-to-work checks were carried out or face the possibility of a £10,000 fine per illegal worker.
Commenting on the raids Jo Liddy, regional director of the UK Border Agency in the north-west, said: “We will not tolerate illegal working, in Preston or anywhere else – it undercuts British wages and exploits vulnerable workers.
“As long as there are illegal jobs, the UK will be an attractive place for illegal immigrants. That’s why we have to put a stop to employers who don’t play by the rules.
“Our new Local Immigration Teams will enforce the full range of immigration laws, concentrating on intelligence gathering, the disruption of illegal activity, tracking down and detaining immigration offenders and failed asylum seekers, and tackling illegal working.”