Just wondering what started the ball rolling on this.
.
The consensus elsewhere is that a cosy relationship existed with local plod, but then a girl who worked there got pulled up for mortgage fraud. Part of that investigation highlighted how much she made working at Sandys. Suddenly a higher / different authority did some calculations on what other girls were making, and how much the owners must be making, and realised there was a big pot to go after.
The local cosy relationship had to stand down and might even have been annoyed at not knowing how much was being made, and the authorities are now going after them on tax evasion (there's always bound to be some in a cash business like this) with the fallback of POCA.
Boris is going to need the cash to grease some wheels to help his American chums privatise the NHS.