Vodafone has sacked several employees over the privacy leak that exposed up to four million customer records.
The telco fell into hot water following allegations that criminals had been sold access to its sensitive customer database and planned to use the information, which included voice and SMS logs, to blackmail customers.
Vodafone subsequently started an investigation, which is still underway. As a result of its findings up to this point, Vodafone has terminated the employment of several staff members and referred their actions on to the New South Wales Police Service.
ZDNet Australia contacted Vodafone to confirm how many staff members had been terminated and where they worked, but the telco refused to provide specific details as they were part of the ongoing investigation.
Vodafone also said it was improving its security.
"We take data security and the storage of our customers information extremely seriously," VHA CEO Nigel Dews said in a statement.
"Some of the initiatives we had already planned for this year are being brought forward and we will also be conducting an additional independent security review."
Following the Vodafone breach on Monday, Optus said it would also conduct a review of its security policies.
Law firm Piper Alderman said this week it is investigating whether or not to include the breach of customer details in its class action against the telco. According to The Australian Financial Review this week, 15,000 people had signed onto the action, up from 9000 just over a week ago.
Vodafone contacted customers earlier this week via email, assuring them that their details were not available publicly on the internet.