In the days of much lower declared values on tapus, I understand the Turkish tax men around Fethiye were looking at transactions where developers and agents were taking (with Power of Attorney) large sums from client bank accounts to pay for properties. Nothing unusual in that, but the taxman cunningly saw that the agent/builder took (say) £50,000 from the customer's bank account to pay for a property which clearly showed it's value on the official tapu as (say) £17,000.
They asked the agent/builder what happened to the other £33,000 they withdrew using PoA, and there really is no worthy reply to that. The taxman would then confirm that as the money could not be accounted for, it can only be put down as profit, and a tax demand was made for the sum in question. It is pretty unfair as they didn't get the money, but had no way of explaining it to the satisfaction of the taxman.
The taxman, of course, knew exactly where the money had gone and I am sure enjoyed it all immensely.
When collecting taxes is the job in question, this makes hugely greater return per taxman hour than turning up mob handed 3 or 4 times to try and catch a family on holiday - in the pursuit of the income tax due on £250.