Five arrests were made at a Sheffield restaurant in a crackdown on illegal workers.
The Home Office-led raid was among a wave carried out nationwide in a crackdown on immigration crime, which led to more than 140 arrests altogether.
Officers were looking for immigrants unable to legally work in the UK and those living in the country illegally, with a view to deporting them.
Employers found using illegal labour face fines of up to £10,000.
In Sheffield, immigration enforcement officers raided Shapla, an Indian restaurant on Cumberland Street in the city centre, and arrested three Bangladeshi men for immigration offences – a 29-year-old suspected of staying in the country for longer than he was permitted, a 29-year-old suspected illegal entrant, and a 34-year-old suspected of using false documents.
Two other men, aged 61 and 38, were arrested on suspicion of knowingly employing illegal workers.
Mark Bates, from the Home Office Criminal Investigation team, said: “We are working hard across Sheffield to track down and remove from the country those who seek to abuse the UK’s immigration laws.
“Illegal working is not a victimless crime. It defrauds the taxpayer, undercuts honest employers and cheats legitimate job seekers out of employment opportunities. “We are happy to work with businesses to let them know what checks need to be made on staff, but those who break the law should know that they will face heavy fines.”
Immigration Minister Mark Harper said: “The operation highlights the routine work we are carrying out every day to stamp out illegal working.
“We are sending a clear message to employers who choose to use illegal labour – we will find you and you will pay a heavy penalty.”