Are you asking a trick question?!!! You are asking for something that not even the Australian Federal Police can guarantee.
How could any fellow punter here give you an assurance when we do not know the circumstances of any worker? Perhaps the best answer is to tell you not to go to any shops that employ Asian or any other foreign workers because any of them could be sex trafficked. And none of the girls will ever admit it to you anyway for fear they will get hurt.
In summary, do not pay for sex at brothels, massage shops or escorts, and then you will be 100% sure you are not a consumer of sex-trafficked humans.