The Indian eaterie in Pittencrieff Street was visited around 5.30pm and officers spoke to staff at the business to establish whether the men had the right to be and work in the UK.

The five men, aged 29, 33, 40, 54 and 66, were arrested for immigration offences and have been detained while steps are taken to remove them from the country.

The restaurant's Facebook page insisted on Saturday that it was "business as normal" after what they described as a "routine check".

But the owner will be issued with a notice warning that a financial penalty of up to £20,000 per illegal worker will be imposed unless they can demonstrate that appropriate right to work checks were carried out.

Stephen Roarty, from Home Office Enforcement Immigration, said, "As this operation demonstrates, we are working hard to clamp down on those who abuse the UK’s immigration system.

“Using illegal labour is not a victimless crime. It cheats the taxpayer, undercuts businesses who ply an honest trade and deprives legitimate job seekers of employment opportunities.

“There are simple checks employers can carry out to ensure their employees have the right to work in the UK. Those who chose to ignore the rules will face the consequences.

"I would urge anyone with detailed and specific information about suspected immigration abuse to contact us.” On Saturday, a message on the Royal Bengal's Facebook page said, "Hello Dunfermline !!! Just wanted to let everyone know it's business as normal at the Royal Bengal.

"As a lot of you may have heard we were visited by the department of immigration last night on a routine check.

"We were also visited at the same time by the fire service, health and safety, HMRC and the council.

"The reason we closed last night was because it was a four hour process and simply there was no point opening the restaurant at 9.15pm.

"We have had a lot of phone calls today and we would like to thank you all for your support. We are open tonight and every night at The Royal Bengal."