The release of the report, described as "proactive" by the council, comes after four months of community pressure following the announcement of the Pinnacle Integrity investigation result in December, which said there was "no evidence that the CEO directly contributed to the letters".

The council resolved in December to "proactively consider and seek advice" on whether the full report could be released in accordance with the Government Information (Public Access) Act, and has since consulted with third parties.

Mr Bath welcomed the release of the report on Wednesday, while complainant Bob Cook said it confirmed his belief that it was "not a true investigation".

The report outlines the steps taken to conclude there was insufficient evidence that Mr Bath behaved in a manner that constituted a breach of the council's code of conduct.

The Herald has previously reported the investigation probed two allegations - whether Mr Bath passed on confidential information to Scott Neylon which Mr Neylon included in letters to the Herald or that Mr Bath wrote one of the letters, which related to the Newcastle Maritime Museum.

The Herald received 18 letters to the editor from Mr Neylon, five of which were published. The Herald was not contacted by the investigator. The report states Herald articles were reviewed but did not form the basis of allegations probed.

Interviews were conducted with the two complainants: maritime museum president Bob Cook and lord mayor Nuatali Nelmes. Mr Neylon provided written responses to questions asked by the investigator, while Mr Bath was not formally interviewed but was spoken to twice, and provided information.

The interviews were conducted between August 24 and October 25, 2023. Interviews were voluntary, conducted on notice and each person was given an opportunity to speak freely. The report said the interviews remained the property of Pinnacle Integrity.

Numerous emails between Mr Bath and Mr Cook were reviewed as part of the investigation after Mr Cook said Mr Neylon's letters contained information only known by himself and Mr Bath.

The investigation did not find that an unpublished letter written by Mr Neylon to the Newcastle Herald in July 2023 contained confidential information only known to Mr Cook and Mr Bath.

A letter from 2019 was excluded from the investigation due to clause 4.4 of the council's administration of the code of conduct, which states a code of conduct complaint must be made within three months of the alleged conduct occurring or within three months of the complainant becoming aware of the alleged conduct.

Clause 4.5 states a complaint made after three months can be accepted if the allegations are deemed "serious and compelling grounds exist for the matter to be dealt with".

The report includes some redactions, including the identity of an MP mentioned by the lord mayor as having "animosity" towards the council.

Mr Bath said he welcomed the release of the full report.

"I have at all times made myself available to the conduct reviewer, undertaking both verbal and written interviews," he said.

"I understand why securing the release of the report has taken time, given the NSW Government's model code of conduct policy makes a presumption against the release of the investigation report where no breach of the code has occurred.

"Releasing a report when the NSW government's own procedure states that it should not occur, is legally complex and time consuming.

"The report confirms what I have always said: I did not write letters to the Newcastle Herald published under the name of my friend Scott Neylon."

Mr Cook said the release of the report "confirms" his belief that it was "not a true investigation".

"It certainly is two people who are the best of friends telling the same story," he said.

"The report hasn't verified whether things either of them said were the truth.

"The report uses words that concern me - reasonable, plausible, conceivable. Those are not the words of an investigator that's proving anything."

Pinnacle Integrity said in a statement that it accepted some people will be "disappointed or dissatisfied" with the investigation result.

"The reviewer's role is to establish the truth having regard to available evidence," the statement said.

"It is a scrupulously objective, independent, and fair process.

"Conduct reviewers do not; hold coercive legislative powers, interrogate witnesses, seize records, nor enforce participation in the process. Witnesses voluntarily participate in the process.

"The review is neither prosecutorial nor it is an inquisition seeking to apportion guilt to validate a predetermined or preferred outcome.

"In this instance, there is a published prevailing view that our role ought to have been to prosecute a person subject of complaint to ratify a preferred finding. That is not, and will never be, our role. Our role is to assess available evidence, rather than rely on inference, assumptions, or inuendo (sic).

"It is accepted that some parties will be disappointed or dissatisfied with the outcome of complaint inquiries. That is inevitable and unavoidable, but does not dictate or influence investigative outcomes."

Read the City of Newcastle and Pinnacle Integrity's statements on the report's release in full here.