The father of a toddler found dead in a Gore oxidation pond four years ago says he has evidence his son did not drown, and wants the case reopened as a murder investigation.

Paul Jones was speaking after the sentencing of the Gore District Council on Monday in relation to the death of Lachie Jones (3) on January 29, 2019.

Mr Jones said there had been ‘‘two, sub-standard police investigations’’ and he could not move on until he found out the truth.

He had a report from an independent pathologist overseas who had challenged the police’s finding, and which lent weight to the opinion of another pathologist, commissioned by the police to review the original postmortem finding, who had expressed similar doubts.

He wanted the case to be relaunched as a homicide investigation by police from outside the region, and demanded Police Commissioner Andrew Coster contact him.

‘‘I want him to show some empathy, and front me, and get this reopened.’’

He had never blamed the council or the state of the ponds’ fencing for his son’s death, he said.

There were people living in the town with information that could help a new investigation, and he urged them to come forward.

Police found Lachie lying in the southernmost of two council wastewater oxidation ponds in Grassland Rd about 10.20pm on January 19, 2019, about two hours after police were notified he was missing.

They originally concluded Lachie had wandered off and his death was an accident.

In March 2020, WorkSafe charged the council under the Health and Safety at Work Act on the grounds the fencing around the ponds was inadequate.

However, Mr Jones doubted his son had walked so far, so late, with a full nappy and bare feet, and wrote to Commissioner Coster requesting the investigation be reopened.

Police did so in late 2020, but about 12 months later announced they had wrapped up the case and referred it back to the coroner.

The council initially denied the charge, and a five-day trial was scheduled for late January.

However, WorkSafe amended the charge in December from a breach causing a serious risk of death to one of the council failing to ensure a workplace was without risks to the health and safety of any person.

The council admitted the amended charge in January.

In his sentencing remarks, Judge Russell Walker said his role was to deal solely with the charge before him, and not to ‘‘engage in any wider inquiry’’.

A section of wooden fencing at the public entrance to the ponds, one of two locations where the fencing was inadequate, had ‘‘effectively provided a ladder’’ for the public to access the ponds at a point only 200m from the nearest houses. He ordered the council pay Lachie’s parents $55,000 each in reparation, and after making deductions for its previous clean record and expression or remorse, quantified a fine of $82,500.

However, he would not impose the fine because it would place an unnecessary burden on the district’s ratepayers, he said.

He ordered the council pay WorkSafe’s costs of about $19,000.

Still fighting . . . Paul Jones after the sentencing of the Gore District Council on Monday. PHOTO: RHYVA VAN ONSELEN

Reading his victim impact statement in court, Mr Jones said Lachie’s death affected him ‘‘every moment of every day’’.

‘‘I’ve lived with the heartbreak, the grief, the trauma, and it has seriously impacted all aspects of my life.’’

Because of his battle to find out the truth, he had not been able to ‘‘move ahead and go through the normal process of grieving’’.

WorkSafe counsel Rachael Woods said the fencing around the two ponds was below the necessary standard in two locations, and it was ‘‘eminently foreseeable’’ a child could enter the area.

The council’s counsel, Garth Gallaway, said there was no evidence of other children being inside the fence in the ponds’ 50-year history.

‘‘It’s not clear how [Lachie] made his way to the ponds and got in the water.’’

The council was represented in court by chief executive Stephen Parry, who in a media statement said it ‘‘apologised unreservedly’’ to Lachie’s family.

After reviewing the circumstances leading to the tragedy, it had renewed and strengthened fencing around all three of its ponds, Mr Parry said.