NSW Premier Gladys Berejiklian has announced her resignation following the announcement that the state’s corruption watchdog would be investigating her.

The NSW Independent Commission Against Corruption (ICAC) said it would probe as to whether there was a conflict of interest during her relationship with former MP Daryl Maguire, with whom she had a “close personal relationship” for five years.

Ms Berejiklian said she had always acted with integrity.

“I want to be clear, and all the decisions I have made as Minister or Premier of New South Wales, my first consideration has always been the well-being and welfare of the people of this state,” she said.

“I state categorically I have always acted with the highest level of integrity. History will demonstrate I have executed my duties again with the highest level of integrity for the benefit the people of New South Wales for who I have had the privilege to serve.

The investigation will probe as to whether Ms Berejiklian breached public trust when she awarded grants to several community organisations between 2012 and 2018. She will be questioned about grants either awarded or promised to the Australian Clay Target Association in Wagga Wagga and the Riverina Conservatorium of Music in Wagga Wagga when Mr Maguire was a local member.

Mr Maguire resigned after he admitted to a separate ICAC that he had sought payment over a property deal. Following this, Ms Berejiklian said she “ceased all contact” with him.

The public hearings will be held as part of  Operation Keppel from Monday, 18 October.