The Independent Broad-based Anti-corruption Commission and Victorian Ombudsman released their joint report into branch stacking allegations by the party.

The watchdogs considered whether the identified misconduct constituted criminal offending that should be referred to the Director of Public Prosecutions, and ultimately opted against it.

“Although the deliberate and extensive use of electorate officers and ministerial advisors for party-political purposes was unethical, and offends right-thinking people’s sense of propriety in the use of public funds, the conduct is not sufficiently clearly captured by any existing statutory provision or the common law offence of misconduct in public office,” the report reads.

“Although we consider the conduct to be egregious, the difficulties in proof are such that we cannot recommend prosecution.

“Rather, it will now be a matter for the Privileges Committees of each house to decide whether the named MPs have wilfully brought discredit upon parliament.”

The investigation was launched following allegations that Labor moderate faction powerbroker Adem Somyurek handed over cash and used parliamentary employees to create fake branch members and amass political influence.

“Branch stacking” involves recruiting or signing up members to a local political party branch to influence parliament candidate preselections.

The practice is not illegal but is against Labor party rules.

The inquiry found branch stacking was not limited to one Victorian Labor faction but evidence of misconduct only concerned Somyurek’s moderate faction.

“We had no specific evidence that allowed us to determine the extent of misuse by any other faction,” the report said.

Somyurek quit the Labor Party in June 2020 before he was expelled after a Nine Network investigation caught him handing over cash and using parliamentary staff to create fake branch members.

Somyurek’s factional allies Robin Scott and Marlene Kairouz also departed cabinet following the expose. All three MPs have previously denied wrongdoing.

About 1700 “non-genuine” Victorian Labor members were subsequently expelled following an internal audit and the state branch remains under the federal control, with rank and file voting rights suspended until 2023.

Luke Donnellan became the fourth ministerial casualty of the scandal in October after then-federal MP Anthony Byrne told the joint inquiry that the pair paid for others’ Labor memberships.

Over the course of public hearings, Somyurek said he was aware of branch stacking when he joined the party in the 1990s, describing it as “deeply embedded” within the party and admitted some of his electorate staff were “factional operatives”.

The former party powerbroker turned crossbencher denied forging signatures on membership forms as part of the operation and misappropriating public funds.

-AAP