About 1000 Australians were found in the so-called Panama papers, which leaked details of potential tax evasion across the globe.
"Some have very serious questions to answer," tax commissioner Chris Jordan told a Senate hearing on Wednesday.
The Australian Taxation Office has raided six accountants and 60 of their clients, while a further 100 people have been contacted.
Mr Jordan said a many of the accountants use a firm in Hong Kong, which instructed the Panama law firm to set up the tax structure.
