· In short: Planning department official Katie Joyner was accused in February of using insider information to buy a house in a Sydney suburb set for rezoning.

· The accusation was made under parliamentary privilege by Opposition MP Alister Henskens.

· ICAC on Monday found there was "no evidence" Ms Joyner engaged in corrupt conduct.

The NSW corruption watchdog has cleared a public servant accused under parliamentary privilege of using secret information to buy a house in a Sydney suburb set for rezoning.

Opposition MP Alister Henskens used parliamentary privilege to raise allegations of corrupt conduct against Planning Department official Katie Joyner, sparking an Independent Commission Against Corruption (ICAC) investigation.

Mr Henskens told parliament Ms Joyner used insider knowledge of plans to rezone land within 400m of Gordon train station in Sydney's north to buy a $3.8 million home in the area.

He also accused the official of offering to tell her new neighbours about the government's unannounced plans "verbally", so they could sell to developers as a group.When Mr Henskens first raised the allegations in parliament in February, he did not name Ms Joyner, saying his information had come from a whistleblower.

But the ICAC has released a statement saying it has reviewed the allegations and found no evidence of corrupt conduct.

"The Commission is satisfied there is no evidence that Ms Joyner or any other person engaged in corrupt conduct, and has accordingly determined to close its investigation," the statement said.

"During the course of its investigation, the Commission obtained and reviewed relevant records… conducted a number of interviews, including with Ms Joyner, and conducted forensic reviews of electronic devices.

"The Commission also undertook a review of the timeline of the TOD process, and when Ms Joyner became aware of the relevant TOD affecting the area in which she purchased property."

TOD, which stands for Transport Oriented Development, is a state government policy to rezone areas around transport hubs for greater density housing.

Mr Henskens had raised allegations in parliament that Ms Joyner sent a WhatsApp message to a group of neighbours in December, saying she was "happy to share what information I can verbally as the information is due to go in the NSW Department of Planning website by the end of this week."

He also accused the Minns government of failing to launch an investigation into the planning department over the matter.

"There is a government cover-up going on here," he told parliament last week.Ms Joyner was suspended the day after the allegations were referred to ICAC in February and remains on leave.

'Unfair allegations'

In a statement issued through her lawyers, Ms Joyner said she had always behaved in line with the expectations of her employment.

She welcomed the outcome, saying the "unfair allegations" should never have been made public.

"I value the work that I do as a public servant and would never compromise the duties that I owe as a public servant," she said.

"I said from day one that I have acted with the utmost propriety, and I am glad that the truth has prevailed. My partner and I have been severely affected by these unfair allegations.

"I will seek legal advice as to what legal avenues are available to me."

Planning Minister Paul Scully said Mr Henskens should apologise to Ms Joyner.

"This is an extremely embarrassing situation for the shadow attorney-general," he said.

"His assessment and judgement of what he identified as a 'highly circumstantial case' has proved to be nothing more than a baseless political attack.

"The leader of the opposition should ask Mr Henskens to apologise."

In a statement earlier today, Mr Henskens said he would speak to his "confidential source" about the ICAC's findings.

"Until I have had those discussions, I won't be making any further public comment," he said.