The oldest Indian restaurant in Chippenham said it is in danger of having to close after it was one of four in the town raided by immigration enforcement officers.
Ten arrests were made in a swoop last Thursday, with four Indian restaurants targeted simultaneously at 6.15pm.
Akash, Ashoka, Cafe India and Taj Mahal could face a fine of up to £20,000 per illegal worker unless they can prove they carried out the correct right-to-work checks.
At Akash, staff said this size of potential penalty might force them to close.
It was the first time it had been raided in its 35 years on The Bridge.
Manager Nurul Islam said they are under increasing pressure from a multitude of Indian restaurants that have opened in the town.
He said: “Times are extremely hard. Thirty-five years ago we were the only one but now there are a lot of us in town.
“It is difficult to get the right staff, to find staff locally. Nobody wants to work the hours, very long, unsociable hours, and it is repetitive work, mopping, no one wants to do it.
“It is hard, if we are fined we may have to close.”
The Home Office allege a 25-year-old man and a 29-year-old man overstayed their visas and a 28-year-old man entered the country illegally.
Officers also seized an amount of cash under the Proceeds of Crime Act.
Mr Islam said it was a dreadful experience.
He said: “I understand that people who have no right to be here shouldn’t be here, but I did the necessary checks. One was working for me and two were helping me for dinner and accommodation.
“The way they handled it was awful, no one was allowed to move.”
At Ashoka in Market Place, a 24-year-old was arrested on suspicion of working in breach of his visa conditions.
Manager Swapan Roy said: “I am sure he’ll be released without action. I’m hoping he’ll be back. We are very careful and checking all.”
He said he understood the authorities were under pressure to catch illegal workers and their operation had not been disruptive.
He said: “Recently we are having serious trouble finding staff, but that doesn’t mean we need illegal immigrants.
“My chef is a partner so we never had a problem with the chef, he’s completely steady, which is good because we have a lot of repeat customers and they want the same taste.”
At Cafe India in New Road, it is alleged a 25-year-old man and a 27-year-old man overstayed their visas and a 32-year-old entered the country illegally.
Manager Radia Choudhur said: “It was a shock. Just because I have someone in my restaurant it does not mean they work here, anybody could come in.”
At Taj Mahal on The Causeway, a 31-year-old Indian man and a 34-year-old man were accused of overstaying their visas and a 21-year-old of working in breach of his visa conditions.
Owner Akhlaq Miah, who took over the business from his father Arju just seven weeks ago, said the 31-year-old was just visiting. He said he has the correct paperwork for the 34-year-old and the 21-year-old is a stident who is qualified to work but just needs a work placement letter from his college.
His father, Arju, said: “We respect the law and we always always try to abide by the rules. This was a technical issue and we have put things right.”
All the suspected illegal workers were Bangladeshi nationals, apart from the Indian national. They were all transferred to immigration detention pending removal from the UK.
The Home Office said they were acting on intelligence from the public and other sources.
A spokesman said: “We treat all allegations of illegal working extremely seriously, and those who ignore the rules will not go under our radar.
“Rogue businesses in Wiltshire are encouraging illegal immigration and undercutting honest employers. It is the employer’s responsibility to check their staff have permission to work in the UK and we are happy to work with those who play by the rules.
“Those who choose not to carry out these checks can expect enforcement visits and financial penalties.”