Turnbull's name emergedin the Panama Papers as a former director of Star Technology Services Limited, a company incorporated by Mossack Fonseca.
"There is nothing new there. The company concerned was a wholly owned subsidiary of a publicly listed Australian company," the prime minister said, according to media reports.
"The involvement is very, very well known," he said.
Acompany register document showedhe was the former director of the company in 1990s and also listed Turnbull's business partner, former NSW premier Neville Wran.
"The company of which Neville Wran and I were directors was an Australian listed company and had it made any profits - which it did not regrettably - it certainly would have paid tax in Australia, but obviously you haven't studied the accounts of the company concerned," Turnbull said.