Eighteen workers are facing removal from the country after a series of immigration raids in the Bath area.
Officials from the Home Office visited four restaurants and takeaways last Thursday, forcing all of them to shut for the night.
The department said all 18 people were staff originally from Bangladesh who had been working illegally.
Immigration enforcement officers simultaneously visited the premises at 6.30pm and carried out checks on staff.
At Saffron in Bath Road, Peasedown St John, all six members of staff on duty were found to be illegal workers and arrested.
At Panahar in Moorland Road, checks revealed that six more men were working illegally.
Three men were arrested at Boojon Tandoori, in Charles Street, and a further three arrested at Herbie's Fish and Chip Shop in Moorland Road.
The three men arrested at Boojon have since been placed on immigration bail and must report to a local police station while the Home Office arranges their removal from the UK.
The other 15 offenders were first taken to police stations but have since been taken to immigration detention centres pending their removal from the country. The men will have the opportunity to put their case against being deported.
The Home Office says the 18 workers were found to have committed a range of immigration offences including overstaying visas, entering the country illegally and working in breach of the conditions of their visas.
Bosses at the four businesses will now have to provide proof to the department that the correct pre-employment checks were carried out or face penalties of up to £10,000 per illegal worker.
Kenny Chapman, assistant director of immigration enforcement in the South West, said: "These successful raids in Bath show that we will track down immigration offenders wherever they are.
"There is no hiding place for people breaking the law and we will seek to remove anyone who we find to be in the UK illegally.
"We want members of the public with information about suspected immigration abuse to get in touch."
Manager of Panahar, Jashim Ahmed, who has run the business for more than ten years, said he had been overwhelmed by the support he had received from customers since the arrests and remained confident the situation would be resolved.
He said: "Most of my staff left last year because of the Olympics – they wanted bigger pay in London. I have struggled with people coming in and out. I can't get my team set. They have not been working here long.
"I am waiting to hear from the Home Office as to what is their situation.
He added: "I have no words for the amount of support I have had from my customers. I'm really out of words – I am just blessed by all the people. I am so thankful."
The business is popular with students, who have been tweeting their support since the raids.
Employers unsure of the steps they need to take to avoid employing illegal workers can visit www.ukba.homeoffice.gov.uk/business-sponsors/preventing-illegal-working/ or they can call the Employers' Helpline on 0300 123 4699.
Anyone with information about immigration offenders can contact www.ukba.homeoffice.gov.uk/aboutus/contact/report-crime/ or Crimestoppers on 0800 555 111.
