Nearly 350 illegal immigrants have been working for the government in some of the country’s most sensitive offices, including the UK Border Agency, it has been disclosed.

An investigation by a Sunday newspaper found that Whitehall, councils and NHS trusts had employed 349 illegal foreign staff over the past four years.

The Home Office admitted employing a dozen illegal workers, 11 Nigerians and a Ghanaian. Ten were cleaners at Beckett House, the headquarters of the UK Border Agency, which is responsible for vetting immigrants, the disclosures under the Freedom of Information Act by the Mail on Sunday revealed.

Three government departments, 34 local authorities and 54 NHS Trusts admitted hiring a total of 349 illegals since 2006. Six were employed as teachers at secondary schools, while four became doctors, according to the newspaper.

Shadow home secretary Chris Grayling said: “The most worrying thing about this is that the Home Office clearly carried on employing illegal immigrants despite being warned two years ago that there was a problem.

“It suggests that the security in the Home Office is inadequate and that Ministers are complacent about the issue.”

None of the bodies involved had yet been fined for employing illegal workers, despite new new immigration legislation in 2008 threatening to fine companies up to £10,000 per illegal worker hired.

A spokeswoman for the Home Office said: “The 12 illegal workers identified since 2006 were all sub-contractors, none of them were directly employed by the Home Office.”

Employing foreign nationals

An employer who hires an illegal worker without carrying out all the necessary checks will be liable to a civil penalty of up to £10,000 for each person that they illegally employ. There are a number of resources on XpertHR to help employers understand the law on employing foreign nationals.