But the owner of the restaurant hit back, claiming that all checks had been made and he was treated like a criminal during Friday evening's raid by immigration officers and police.

The six employees, all Indian men, were arrested on suspicion of being illegal workers at the Saffron restaurant on Buchanan Street in an intelligence led operation by officers from the UK Border Agency.

They were all charged with immigration offences, and their employers could be hit with up to £60,000 worth of fines — £10,000 for each illegal worker employed.

Bali Gill, a partner in the business, said: "Fifteen officers came rushing into the restaurant and made us feel like criminals.

"We just wanted them to talk to us calmly and tell us what it was all about.

"We had carried out all the checks we thought were necessary, we had all the staff's National Insurance numbers and supplied them.

"I don't understand how we are meant to know whether they are genuine or not.

"They need to find out where people are getting fake National Insurance numbers from, that is the real problem.

"We are just giving people jobs and if they can't work anymore they will just turn to crime.

"Businesses like mine are being bullied by immigration and forced to close.

"We have no staff now and they are difficult to find."

This was one of many raids that have been carried out throughout Scotland recently and after checking the staff documents, steps are being taken to remove the six men from the UK.

They were all weekend staff. Some had been working at the restaurant for as long as eight months and others were only on a three week trial. The owner of the restaurant was issued with on-the-spot notices, and warned that he may receive civil penalties for employing illegal workers. If further investigations show that proper checks were not undertaken to employ the workers, he could face thousands of pounds of fines.

Phil Taylor, regional director of the UK Border Agency in Scotland and Northern Ireland, said: "The UK Border Agency is carrying out operations like this throughout Scotland every week.

"Employing illegal workers is harmful to our communities, and we are determined to step in and identify those employers who are breaking immigration laws and to remove those people who do not have the right to be in the UK."

To avoid employing illegal workers visit www.bia.homeoffice.gov.uk/employers/ or call the UK Border Agency Employers Helpline on 0845 010 6677.

If you suspect illegal workers are being employed somewhere contact Crimestoppers on 0800 555 111 anonymously.