Sorry to rub it in but I think £500.00 is the minimum that they can have as I have heard of an amount of £3K being mentioned.

What I can't understand is that the onus is on the UK Border Force to prove who the person is, surely it should be on the person arrested to prove who they are and where they are from!

If the UK Border Force can't prove who the person is then that person is released with certain conditions attached such as reporting to the local Police on a weekly basis.
It's not rocket science but that illegal is going to abscond and that is what they do, so they have to chase the person again and if caught repeat the same procedure, :rage: