The number of employers prosecuted for hiring illegal immigrants has rocketed by 513%, according to Home Office figures.
New laws introduced in February 2008 have led to a record 233 firms prosecuted for employing illegal immigrants. Before the legislation changed no more than 38 cases were brought against employers in any year.
Under the Immigration, Asylum and Nationality Act 2006, which introduced the UK's new points-based system, the onus is on employers to make sure employees are legally entitled to work here.
Firms face fines of up to £10,000 for each illegal worker they employ, and more than £3.4m worth of fines have been dished out already.
The new data was obtained by HR service provider Giant Precision. According to the company, the system means recruiters and employers should ensure that their background checking systems are up-to-date with the new legislation.
Matthew Brown, managing director, said: "The new civil penalty for employers who hire illegal immigrants has made a big difference to the UK Border Agency's activity in bringing cases against employers. More employers than ever before are finding themselves hit with big fines.
"In cases where an illegal immigrant is supplied by a staffing agency, the agency itself can be liable."