Better get this one back on topic guys. If audited the onus is...

Better get this one back on topic guys. If audited the onus is on you to provide the information. Austrac systems would show the money flow and it would be up to you to substantiate that you haven't washed the credits. These days it would be part of a multidisciplinary audit, featuring GST, SMSF etc...with the potential for washing getting flagged through initial analytics as part of the greater audit. Just do the right thing - but if you don't know the answers to these things you are likely too small (in terms of high wealth) to worry about it.

Not an ATO employee, for the record.