Eleven people have been arrested in an immigration raid at a top London hotel.
A probe carried out on Wednesday found that the agency workers had been working illegally as cleaners, porters and maids at the four-star Regents Park Marriott Hotel.
The staff were being significantly underpaid, receiving only half a normal salary for their 15 hours a week of work under two separate subcontractors.
Five of the staff were detained pending their removal from the country, while a further six were bailed and will be required to report regularly to the Home Office, said officials.
The staff, who were of six different nationalities, did not have the right to work in the UK. One of those arrested had been smuggled into the UK illegally, said the Home Office.
The immigration enforcement visit was arranged with the backing of the hotel chain and took place as part of a crackdown on unlawful employment in hospitality.
The employers of the agency staff working at the hotel are facing fines of up to £20,000 per worker after being handed a civil penalty referral notice.
Suran Padiachie, Deputy Director of Immigration Enforcement and Compliance at the Home Office said: “I’m grateful to Marriott for their cooperation with this case. Their support allowed my officers to swiftly identify the illegal workers and take action against their third party employers to ensure they face appropriate sanctions.
"Illegal working exploits vulnerable people and damages the economy, which is why we’re using the full weight of the law to clamp down on rogue employers and remove those with no right to be in the UK."