It's been a big problem for a long time.
To play a match for $10,000 in Britain, IF you win, deduct your expenses......
.....and if highly publicised, the gov wants 30. points.....
....you'll find you were laying 2 to 1....and that's when you're betting your own money.
I think that was part of the Dipster's consideration when turning down Daz.
Anything over 10g's is supposed to be declared then the alarm bells start ringing next thing you know your in the back room of the airport with a strangers fingers up your bottom.