The Australian privacy commissioner has opened a formal investigation into Facebook after the social network revealed more than 300,000 Australians had been caught up in its global data harvesting scandal.
Facebook's chief technology officer earlier today said the company believed the information of up to 87 million people had been improperly shared with political consultancy Cambridge Analytica.
Earlier estimates by the two news outlets who broke the story had put the number of affected individuals at around 50 million.
Within that 87 million were 311,127 people in Australia, Facebook said today.
Acting Australian privacy commissioner Angelene Falk had made "inquiries" of Facebook as to whether any Australians had been impacted when the story broke last month.
Today Falk upped the inquiries to a formal investigation.
"The investigation will consider whether Facebook has breached the Privacy Act. Given the global nature of this matter, the OAIC will confer with regulatory authorities internationally," Falk said in a statement.
"All organisations that are covered by the Privacy Act have obligations in relation to the personal information that they hold.
"This includes taking reasonable steps to ensure that personal information is held securely, and ensuring that customers are adequately notified about the collection and handling of their personal information."
Australia joins several other countries - including the US, where the bulk of the 87 million affected Facebook users reside - to investigate Facebook over the matter.
Facebook today said it was taking steps to restrict the personal data it makes available to third-party app developers.
Separately today, Cambridge Analytica refuted Facebook's claim that it accessed the records of 87 million people.
“Cambridge Analytica licensed data for no more than 30 million people from [research company] GSR, as is clearly stated in our contract with the research company. We did not receive more data than this," it said in a statement.
Facebook's chief executive Mark Zuckerberg is scheduled to testify about the scandal before the US house energy and commerce committee next week.