clearly they are talking about the shared houses / flats with a few Romanian birds working in them. A brothel to them will be a place with more than one bird in it selling her ass.
"For some, they may be working there by choice but if they are, it’s because they feel they don’t have another choice.
...or they do have a choice, have decided that they want to earn a years salary in a fortnight getting pumped in Sheffield, responded to one of the many adverts in Romanian advertising blatantly for hookers.
Funny - with the EE birds, it is sex trafficking. For British birds though they are worried about TAX not being paid. Why not raid the Romanian pimps for Tax evasion?