Three men were arrested after a Home Office raid at a takeaway in Higham Ferrers.
Acting on intelligence, immigration enforcement officers visited Tandoori Takeaway in Market Square, Higham Ferrers, at about 6pm on Thursday, March 5.
Staff at the business were questioned to establish whether they had the right to live and work in the UK.
Three Bangladeshi men were arrested.
Two of them, aged 30 and 25, had overstayed their visas, while a 26-year-old had obtained leave to remain in the UK by deception.
The 30-year-old was detained while action is taken to remove him from the UK, and the other two were ordered to report regularly to the Home Office while their cases are progressed. They will also face removal if found to have no right to remain in the country.
The business was served a notice warning that a civil penalty of up to £20,000 per illegal worker found could be imposed.
The business will be liable to pay this penalty unless they can demonstrate that the correct pre-employment checks were carried out such as seeing a Home Office document or passport. If proof is not provided, this is a potential total of up to £60,000.
Alison Spowage, Assistant Director of East Midlands Home Office Immigration Enforcement, said: “We take reports of illegal working very seriously and will always act where we have intelligence that it is happening.
“Illegal working cheats the taxpayer, undercuts honest employers and often exploits some of society’s most vulnerable people.
“It also means legitimate job seekers are denied employment opportunities.
“If members of the public have any information about immigration abuse I would urge them to report it to us.”
Anyone with information about suspected immigration abuse can visit https://www.gov.uk/report-immigration-crime or call Crimestoppers on 0800 555111.
Information to help employers carry out checks to prevent illegal working can be found at: https://www.gov.uk/government/collections/employers-illegal-working-penalties.