An ongoing Newcastle Herald investigation can reveal that not all complaints about the misleading letters were investigated, with at least one tossed out because it was ruled out of time.

The justification used to exclude the complaint has raised further questions about the effectiveness or otherwise of the code of conduct investigation, which found Mr Bath did not have a case to answer.

Council contractor Pinnacle Integrity's investigation report has not been made public, but the Herald has seen excerpts from the document.

It reveals that a complaint made by Maritime Museum Society president Bob Cook, about a Neylon letter published in the Herald in August 2019, was tossed out because it was lodged more than three months after the letter was published.

But the ruling appears to have ignored part of the timing clause outlined in council's code of conduct procedures.

According to the final investigation report, the complaint about the 2019 letter was excluded under clause 4.4.

"Mr Cook was of the view that the letter was either written by Mr Bath or that Mr Bath provided confidential information to Mr Neylon," the investigation report reads.

"[This allegation did not meet the criteria outlined at clause 4.4 of the procedures and therefore does not form part of this investigation]."

Clause 4.4 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".

The first part of Mr Cook's complaint to Cr Nelmes refers to an unpublished letter to the Herald from July 2023 and a published letter from August 2019.

The second part of Mr Cook's complaint was about the closure of the maritime museum.

A council spokesman said Cr Nelmes referred multiple complaints sent to her from Mr Cook to council's complaints coordiantor, Emily Kolatchew.

"The complaint sent to the lord mayor dated 30 July 2023 was dealt with in line with the procedure and included two parts," he said.

"The part relating to allegations regarding letter writing was referred from the [complaints coordinator] to a third party investigator. The part relating to a separate matter was assessed by the [complaints coordinator] and declined at the outset in line with the procedure."

The council's response failed to address why clause 4.4 was used to exclude the complaint about the 2019 letter.

Mr Cook has made complaints this week to the NSW Minister for Local Government Ron Hoenig and the Independent Commission Against Corruption, claiming his concern about the 2019 letter was "unjustly" excluded.

He believes clause 4.4 was used as part of a "carefully orchestrated plan" to investigate as "little as possible".

If clause 4.4 was applied the way it was to Mr Cook's complaint about the 2019 letter, at least 16 of the 19 letters received by the Herald under the name Scott Neylon would be excluded from investigation.

Only three were submitted within three months of the Herald revealing the links between Mr Neylon and Mr Bath.

"My question is how many of the other letters were not investigated because of this clause?" Mr Cook asked.

"To me it's quite clear that the first part of that clause has been wrongly used to get rid of my complaint.

"There was no regard for the fact that I only just found out about the relationship between Mr Bath and Mr Neylon and that was the reason I wanted the matter investigated.

"The second half of the clause was conveniently ignored."

The latest development has cast further doubt over the efficacy of the investigation, which has so far failed to answer key questions about the long-running controversy that continues to plague the highest levels of the council.

City of Newcastle's code of conduct says whoever investigated Mr Bath "must make any such enquiries that may be reasonably necessary to establish the facts of the matter".

Cr Nelmes declined to answer a series of questions put by the Herald this week about why clause 4.4 was used to get rid of Mr Cook's complaint about the 2019 letter, and exactly what Pinnacle Integrity was tasked with investigating, including how many of the letters were looked at.

Mr Cook, who has been at loggerheads with the council for years over the future of the maritime museum collection, said the inevitable conclusion was that the investigation was designed to make it look like the letters scandal was being examined, but very little investigation actually took place.

Cr Nelmes also declined to answer why she, or her delegate, did not invoke clause 4.5 of the code of conduct procedures, which allows a complaint made after three months if the "allegations are serious and compelling grounds exist for the matter to be dealt with under the code of conduct".

According to Mr Cook, the worst thing about the latest revelation was that the public could have no faith in the council's handling of the investigation into Mr Bath.

"It's become clear that the investigation into the Neylon letters was a non-investigation," he said.

"Nothing to see here, let's all move along. I believe the investigation was a sham, designed to ensure very little was looked at."

Mr Cook lodged his two-part complaint with Cr Nelmes on July 30 last year, just days after learning via the Herald that dozens of letters and online comments had been published in media outlets over 13 years under the name Scott Neylon, which twist the truth, distort reality and follow Mr Bath's career progression, attacking his critics and supporting his employers.

Mr Neylon is Mr Bath's best mate and has lived in Japan since at least 1998.

Mr Bath has repeatedly denied any involvement in the letters.

Several of the letters attack Mr Cook for his role in the maritime museum.

Cr Nelmes was directed last year by NSW Local Government Minister Ron Hoenig to investigate the letters saga.

As CEO, Mr Bath is responsible for City of Newcastle's code of conduct complaints when they relate to staff members. But when the complaint is about the CEO, the lord mayor is responsible.

According to council's code of conduct procedures, when it comes to how a complaint is managed, the lord mayor and the CEO can delegate their functions to a staff member or external person.

Anyone can make a code of conduct complaint against a councillor or staff member, provided it centres on a conduct breach rather than, for example, service delivery or a council policy.

The council-commissioned letters investigation by Pinnacle Integrity found there was insufficient evidence to support any wrongdoing by Mr Bath.

According to a four-page outcomes letter published on City of Newcastle's website, Pinnacle Integrity investigated only two allegations.

The first allegation was whether Mr Bath passed on confidential council information to Mr Neylon, which he included in letters he wrote to the Herald.

The second allegation questioned if Mr Bath passed on confidential information to Mr Neylon which was included in an unpublished letter on 22 July 2023 about the Newcastle Maritime Museum, or if Mr Bath wrote the letter.

Both of these allegations were raised by Mr Cook in his complaint to Cr Nelmes.

Despite the council voting unanimously last year to support an investigation into the letters saga and Mr Hoenig requesting an investigation, there is no mention of Pinnacle Integrity investigating anything beyond concerns raised in Mr Cook's complaint.

According to the outcomes letter, Pinnacle Integrity completed a preliminary assessment of "additional concerns" and reported back to council in September last year.

"Concerns that did not meet the procedural requirements for review were referred back to council," the outcome letter reads.

"Those matters have not been investigated as part of this code of conduct review."

Mr Cook said he now held "grave concerns" that his complaint might have been the only matter investigated by Pinnacle Integrity.

The council's code of conduct and a separate document spelling out how the code should be administered reveal the rules which apply to the investigation.

In accordance with the council's code of conduct policy, all of the investigation and its deliberations were held in secret.

Several councillors called last week for the investigation report into Mr Bath to be made public as soon as possible.

Cr John MacKenzie said it's in "everyone's best interest for the full report to be released as a matter of urgency".

"Right now, the councillors have had to make a leap of faith that the investigator's conclusions are supported by the evidence, but we don't have the visibility of what evidence was used," he said.

Despite Newcastle councillors unanimously voting to "proactively consider and seek advice" for the report to be made public under the GIPA Act back in December and Mr Bath agreeing, we are still none the wiser on what it contains or who is holding up the release.

The council has said it was continuing consultations with third parties to make the document public.

Donna.page@newcastleherald.com.au