UK work permits are one piece of information that businesses should not neglect to check when employing foreign nationals.
Rachel Challis, from the UK Border Agency's (UKBA) Boston-based team, advised any company taking on a foreign national that the authorities are continuing to crackdown on firms that fail to conduct the proper checks on passports and identity documents.
"Any business that takes on a foreign national without permission to work should be aware that they are breaking the law as well as undermining law-abiding employers," she added.
"Rogue employers should be warned that they face heavy fines and could end up in jail."
The comments follow raids conducted by UKBA immigration officers on three business in Spilsby, near Skegness.
Officers discovered seven people employed without the correct UK work permits and documentation.
They arrested a 30-year-old Bangladeshi man at the Charm Spice restaurant on Monday (January 17th)
The move came after the discovery of a further three Bangladeshi men who were arrested at Nasim restaurant in Stone Lane on January 6th, along with an Indian man who had overstayed his UK visa
Meanwhile, on December 15th officers visited Jade Garden Chinese Takeaway and discovered two Chinese nationals who were later arrested after checks confirmed that they were not legally entitled to be employed in the UK.
While the immigrants concerned face being evicted from the country, the businesses concerned face a fine of up to £10,000 for each illegal worker if they are found not to have conducted the proper identity checks prior to employment.