"We have been working closely with the Information Commissioner's Office in their investigation of Cambridge Analytica, just as we have with authorities in the USA and other countries", he added.
Denham also called for the government to introduce a statutory code of practice for the use of personal data in political campaigns, adding that "this can not be at the expense of transparency, fairness and compliance with the law".
The ICO also announced it proposes to bring criminal action against SCL Elections, the parent company of Cambridge Analytica (CA), for allegedly failing to comply with an enforcement notice and allow access to the data it held.
Facebook CEO Mark Zuckerberg has faced questioning by USA and European Union lawmakers over how Cambridge Analytica improperly got hold of the personal data of 87 million Facebook users from a researcher.
"The ICO's investigation concluded that Facebook contravened the law by failing to safeguard people's information", the organisation said in a statement.
The ICO added that it plans to issue Facebook with the maximum available fine for breaches of the Data Protection Act - an equivalent of US$660,000 or €566,000.
Facebook has a chance to respond to the ICO before a final decision is made on the fine. "Trust and confidence in the integrity of our democratic processes risk being disrupted because the average voter has little idea of what is going on behind the scenes". Facebook initially said the scandal affected about 310,000 Australians in total.
'People can not have control over their own data if they don't know or understand how it is being used.
"We have been working closely with the Information Commissioner's Office in their investigation of Cambridge Analytica, just as we have with authorities in the United States and other countries".
The ICO launched an investigation in March into Cambridge Analytica, the UK-based political data analysis firm at the heart of a scandal that's stirred up two national governments and the world's largest social network.
Mail.Ru told CNN it had not been contacted by Facebook about its investigation into the misuse of user data.
That's why greater and genuine transparency about the use of data analytics is vital'.
It has also said that, while it pitched for work with campaign group Leave.EU ahead of the Brexit referendum in Britain in 2016, it did not end up doing any work on the campaign. "We're reviewing the report and will respond to the ICO soon".
"If other developers broke the law we have a right to know, and the users whose data may have been compromised in this way should be informed".
Facebook could face a hefty compensation bill in Australia after a leading litigation funder lodged a complaint with the country's privacy regulator over users' personal data shared with a British political consultancy.