Berejiklian's shock resignation comes as the state, which has an economy larger than Singapore, Thailand or Malaysia, battles the biggest COVID-19 outbreak in the country and is poised to begin ending months-long lockdowns as Australia sets to reopen international borders in November. read more

Berejiklian said the issues being investigated were "historical matters" but she felt compelled to resign because of the long time frames likely to be involved in the investigation. She also said the state needed certainty over its leadership amid the coronavirus pandemic.

"I state categorically I have always acted with the highest level of integrity" she said at a news conference.