I am acquainted with someone who works in the hotel industry. Among their staff there are four Polish workers. These individuals get free board and lodgings - live in, all found. They never go out, therefore are adding zilch to the local economy. Two days a week, staff have free use of the hotel leisure centre. They are the only four members of staff who make use of this facility. Apart for a few quid for toiletries, their entire wages are posted home. Two are restaurant staff, two kitchen employees. They are not paid any less than English staff doing the same jobs, as is sometimes mooted. The individual I know works in accounts, so she knows this to be a fact.

I have no reason to believe that they are unique. There must be hundreds more doing exactly the same thing.