Four illegal workers have been found at a restaurant in Devon.
The discovery was made during a raid by UK Border Agency staff on the Nibana Restaurant in Crownhill, Plymouth, on Tuesday evening.
The illegal workers are an 18-year-old Iranian man and three Bangladeshi men, aged 22, 24 and 27.
The operation was part of planned nationwide action to tackle illegal working, sham marriages, bogus colleges and organised immigration crime.
After checking the immigration status of staff, three men were found to have no right to work in the UK.
They have immigration applications currently being processed, but do not have permission to work.
If these applications are turned down, the men will be deported.
One of the men told officers he had permission to work in the UK and initial checks indicated this was the case, but it emerged that his visa had expired in July and he was therefore in the UK illegally.
Officers returned to the restaurant on Wednesday and arrested the 24-year-old Bangladeshi.
He and the 27-year-old man are both being held in immigration detention pending their removal from the UK.
The restaurant was given a civil penalty notice warning the employer a fine of up to £40,000 - £10,000 per illegal worker - will be imposed unless proof is provided that right-to-work checks were carried out on the men.
Immigration Minister Damian Green said: "We are determined to make it harder than ever for illegal immigrants to come to the UK.
"Illegal immigration puts pressure on public services, local communities and legitimate businesses at a time when this country cannot afford it."