At least 18 Indians have been arrested in Britain for immigration-related offences and would be deported soon.
The illegal workers were arrested by the UK Border Agency (UKBA) from two catering firms in west London, a clothing factory in Leicester and a restaurant in Aberdeen.
The arrests were made between July 22 and 29 as part of a nationwide operation by the UKBA to tackle illegal working, sham marriages, bogus colleges and organised immigration crime, a statement from the British High Commission in India said Wednesday.
Steps would be taken for their deportation from Britain, the statement said.
The four businesses were issued warnings that they face up to 180,000 pounds in fines for employing the workers, unless they can prove they carried out correct checks.
"We are determined to make it harder than ever for illegal immigrants to come to Britain. Illegal immigration puts pressure on public services, local communities and legitimate businesses at a time when this country cannot afford it," said Damian Green, Britain's immigration minister.
"That's why the UK Border Agency is working to cut illegal employment, sham marriages, bogus colleges and organised smugglers being used by foreign nationals to try to stay in Britain illegally."