Immigration Enforcement officers descended on the business, acting on intelligence that illegal working was taking place on site.
They arrested 7 men - all Indian nationals - for suspected illegal working.
Four more Indian men were arrested at a nearby cake factory. They were found to be in breach of their visa conditions and one was also working illegally.
An Indian woman was then arrested for immigration offences at a private home, with further raids planned throughout the afternoon.
Four of the offenders were detained pending consideration for removal from the UK. The remaining 8 were bailed on the condition they report regularly to the Home Office.
The 2 businesses could now face substantial fines if it is established they have employed illegal workers and have failed to conduct relevant pre-employment checks.
In February this year, the Home Office tripled fines for employers who allow illegal migrants to work for them. For a first breach this has gone from £15,000 to £45,000 per illegal worker and for repeat breaches within 3 years the fines have increased from £20,000 to £60,000.
Michael Tomlinson MP, Minister for Countering Illegal Migration, said:
This operation is a clear example of the way we are stepping up immigration enforcement activity across the country.
Employers found to be breaching the rules can expect significantly increased fines, and, if workers are found to have no right to live or work here, we will not hesitate to act and remove them from the country.
Eddy Montgomery, Director of Enforcement, Compliance and Crime at the Home Office said:
Illegal working causes serious harm to communities, puts vulnerable people at risk and defrauds the public purse.
The arrests send a clear message that we are clamping down on this dangerous practice.
People smugglers sell migrants the lie that they can work in the UK. The reality is that they can't - and those found to be working illegally or facilitating this crime will face the full weight of the law.
