"We believe we know, which individuals are responsible but I will not be naming them," Kershaw said.
After the recent update on the number of people involved in the Medibank data leak, the hackers have begun posting client data on the dark web.
Now it has been confirmed that the number of affected victims involved in the hacking has doubled to 9.7 million.
Major health insurer Medibank was victim to yet another isolated cyber-attack earlier this month but the CEO revealed it concerns all their customers.