The UK Border Agency is continuing to track down illegal workers in 2011.
Employees who are in the country without a UK work permit are still a target of investigation for the UK Border Agency (UKBA).
Two Welsh businesses have been some of the first firms to be issued with fines in 2011 for hiring people without UK work permits.
Noble City, a restaurant located in the village of Treorchy, was raided on March 26th last year after the UKBA received intelligence that illegal workers were on the premises.
Indeed, a 44-year-old Chinese man was found working in the kitchens without a UK work permit.
As a result, he was deported and his employer was issued with an on-the-spot penalty notice.
However, the business was then given an opportunity to prove that it carried out the correct UK immigration checks on the man before employing him. These inquiries include scrutinising an applicant's UK work permit or passport.
Since Noble City could not provide evidence for these checks they have now been handed a fine of £5,000 as a Civil Penalty Notice.
Jane Farleigh, regional director at the UKBA for Wales and the south-west, commented: "It is the legal responsibility of all employers to check that staff have the right to work in the UK.
"There are simple ways of checking a foreign national's right to work and there are no excuses for failing to do so."
The news come as two further Chinese immigrants have been arrested in the nearby village of Treherbert.
A 22-year-old woman and a 39-year-old man were found to be working illegally at North Lake Limited. The employer has been handed a Civil Penalty Notice for £10,000 for failing to carry out the necessary UK work permit checks before giving jobs to the two people.