Indian students were among 20 foreigners arrested for working more hours than their visas allowed at a warehouse operated by Britain's biggest supermarket chain Tesco, while four of their compatriots were deported to India for illegally staying in the UK.
UK border agency officials discovered that the foreign students, mostly of Bangladeshi and Indian origin, had been working three-and-a-half times longer than their visas allowed for Tesco in Croydon, south London.
Tesco faces a major fine for employing foreign students illegally at its warehouse.
At least seven Tesco employees, who have not yet been identified, have since been deported and several others are still under investigation, officials said.
While those arrested, believed to be aged over 18, had student visas and the right to work in the UK, they are alleged to have exceeded their 20-hour-a-week working limit by up to a further 50 hours in some cases.
Tesco now faces a bill of up to 10,000 pounds per illegal worker unless the company can prove it carries out the legally required checks.
It was not clear how many Indians were among the 20 foreign students arrested.
In another incident, four Indians were among 11 foreign nationals arrested when UK immigration officers visited a company in Chelmsford, east England.
They were found to have overstayed their visas during checks, official sources here said.
Apart from four Indians who have been deported to their country, four were Pakistanis, two Bangladeshis and one was from Sri Lanka.
All were men except the Sri Lankan, who was a 33-year-old woman.
Seven of those arrested at the firm were working in breach of their student visa conditions while four had overstayed their visas, the official sources said.
Those found overstaying their visa would be barred from re-entering the UK in future.
Mark Gear, UK border agency, east of England, said,"Our message to those people with no right to be in the UK is that they must leave. If they volunteer to leave and cooperate with us, we will help and provide support...
"We are creating a hostile environment for illegal migrants.Anyone who overstays their visa should be in no doubt that they will be found, arrested and removed from the UK."