Caught working

The government announced a crackdown on illegal workers. How many illegal workers are caught in Britain?
— From October to December last year, 716 illegal workers were caught, 337 in London and the south-east. Among those caught were restaurant workers in Chinatown, a takeaway worker in Norwich, a fish-and-chip shop worker in Lincoln and a shopworker with sideline in counterfeit tobacco in the Forest of Dean.