Accountants
I had an ex girl friend whose former husband was an accountant. This was his 3rd divorce, and of course being an accountant he knew how to hide his money.
He deliberately ran up large debts on credit cards and then presented that as evidence to the court he was close to bankruptcy - who ever heard of a bankrupt accountant!
He ran an accountancy firm and used to boast he was making £90 per hour.
And every accountant and a very large number of people who are not - know that you don't run up debts on credit cards where the interest rate is very high. He planned the divorce at least 6 months in advance and set about hiding the money and presenting a picture that he was broke.
He got away with it, managed to convince the court he was just about flat broke (despite the fact he owned 4 houses), and she ended up with the princely sum of £50K out of which she was obliged to pay £20K in legal costs.
An accountant's job is to find where people have hidden the money, so he knew the mechanisms used to hide it. And the court had limited powers of investigation, being only a civil case.
Answer? Never get married. The men nearly always are the ones that come worst off in a divorce case, but this case is one exception.