Former NSW police commissioner Mick Fuller should have declared potential conflict of interests by owning racehorses, a report has found.
The Law Enforcement Conduct Commission report published on Tuesday comes after an initial investigation in March.
Mr Fuller should have completed declarations of potential and perceived conflicts of interest which disclosed his ownership of racehorses, the report says.
It called for conflict of interest declarations for all police officers in the interests of a "transparent system".
"The commission recommends ... the Commissioner of Police consider amendment of the NSWPF policy concerning conflict of interests by inserting a reference to gaming and racing as a 'high risk industry'," the report says.
Mr Fuller was forced to defend his past ownership of thoroughbreds during a NSW budget estimates hearing last year.
Mr Fuller was part of a racehorse syndicate that brought the racehorse Mad Magic In June 2015.
The syndicate of 14 included NRL coach Ricky Stuart and businessman Mark Bouris.
Mr Fuller's share in the horse was five per cent.
The horse raced but in early 2017, before Mr Fuller was appointed commissioner, it broke its leg and had to be put down.
He also had a two per cent stake in another racehorse, Once Epona Time.
The report detailed how Mr Fuller verbally informed the then police minister David Elliott, that he had a part ownership in a racehorse.
According to Mr Fuller, the reason for this was not because of any policy requirement, but because of his high-profile position he felt it was the right thing to do.
In his evidence to the commission, Mr Fuller said the minister told him he was "entitled to a hobby".
The report calls for rules regarding police officers owning racehorses with appropriate checks and balances.
A declaration of a conflict of interest was not an admission of wrongdoing, the report says.
The investigation was extended after the LECC inspector raised concerns about an earlier commission report's findings.