A couple things, based on California law (your results may vary). Child support must be based on income, not wealth, although the return on wealth is income for purposes of child support. Second, at least here, the presumption is that all court proceedings are open with limited exceptions like adoptions and juvenile. It’s tough to get stuff sealed. I can’t imagine a court here sealing the amount of child support.
Okay, then in that case, his wealth should be confiscated, as it would for ill-gotten money dealing drugs, and restitution made to the rightful owner of the money, the taxpayers (via returning to the US Treasury).