The employment of illegal workers in many countries carry penalties for the Employer, as well as the employee.
An illegal worker is normally defined as someone in the country without a valid working visa.
Example penalties are:
Australia:
People convicted face fines of up to $13,200 and two years’ imprisonment, while companies face fines of up to $66,000 per illegal worker.
The offences apply to employers, labour hire companies, employment agencies and anyone who allows illegal workers to work or refers illegal workers for work.
http://www.immi.gov.au/gateways/agents/pdf/working_visas_penalities_employers.pdf
United Kingdom:
You can be fined up to £10,000 for each illegal worker or face criminal prosecution.
If you knowingly employ an illegal worker, you can also go to jail for up to 2 years and receive an unlimited fine.
https://www.gov.uk/penalties-for-employing-illegal-workers
Singapore:
Employers who hire foreigners without valid work passes can be prosecuted under the Employment of Foreign Manpower Act
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