Six people were arrested following a series of raids by the UK Border Agency in the York area.
The enforcement operation was part of a nationwide summer campaign to tackle illegal working, sham marriages, bogus colleges and organised immigration crime.
Acting on intelligence, the UK Border Agency visited several restaurants in the Leeds and Selby area on Thursday evening 29 July. At the Hacis Café on Front Street, York, officers questioned staff to ensure they had the right to work in the UK.
Of the six employees who were on site at the time of the visit, three Turkish male nationals were found to have no right to work and have been arrested for immigration offences.
At Parvin Tandoori on Beckfield Lane, York, officers checked documents of the five staff and two Bangladeshi male nationals were found to have no right to work and have been arrested for immigration offences.
Parvin Tandoori has been issued with a penalty notice which means they could now be fined up to £20,000 for employing the two men, unless bosses can prove they carried out the correct right-to-work checks on their employees.
At Le Raj in Ousegate, Selby, officers checked documents of the six staff and a 30-year-old Bangladeshi male was found to have no right to work and was arrested for immigration offences.
Le Raj has been issued with a penalty notice which means they could now be fined up to £10,000 unless bosses can prove they carried out the correct right-to-work checks on their employees.
The UK Border Agency is taking steps to remove all those arrested from the UK.
Damian Green, the Immigration Minister, said:
'The Government has tasked the UK Border Agency with carrying out an intense period of enforcement activity over the summer. We are determined to create a hostile environment which makes it harder than ever for illegal immigrants to come to the UK and put down roots.
'Illegal immigration puts untold pressure on public services at a time when this country cannot afford to support people not entitled to it. That's why the UK Border Agency is working day in, day out to cut out the routes - such as sham marriages, bogus colleges and organised traffickers - being used by foreign nationals to try and stay in the UK permanently.'
Source: UK Border Agency