The Independent Broad-based Anti-corruption Commission on Wednesday said it is investigating "serious allegations of corrupt conduct" within Victorian Labor.

"IBAC's Operation Fortescue will examine a range of matters concerning allegations of branch stacking, and other matters aired recently in media reports, and other related complaints made to IBAC," it said in a statement.

It comes as the state's ombudsman was also asked to investigate the scandal and the party begins a "painful" process of reform.

Secret recordings of now-former Labor heavyweight Adem Somyurek allegedly organising branch stacking and using vile language about colleagues and staff were first aired by Nine on Sunday night.

The expose prompted his sacking from cabinet and he quit the party.

His right-faction allies Marlene Kairouz and Robin Scott later resigned from cabinet, following allegations their staff were connected to Mr Somyurek's efforts.

The scandal prompted Premier Daniel Andrews to ask Labor's national executive to reform the Victorian party.

They were only too happy to oblige, with former premier Steve Bracks and former federal minister Jenny Macklin appointed as administrators of the branch until January.

Voting rights for rank and file members are being suspended until 2023, while every member is audited to ensure they genuinely want to be members and have paid to be so themselves.

Mr Andrews apologised to the party's "true believers".

"I apologise for your pain, and I guarantee you when this reform work is finished, not only will your voice be heard, but it will be louder than it has ever been," Mr Andrews said at parliament on Wednesday.

The lengthy time frame without voting rights is necessary, he stressed.

"Cleaning this up will take some time and you've got to break the business model of those who would seek to undermine the integrity of our systems," he said.

The national executive will need to pre-select candidates for the next federal and state elections.

Mr Bracks and Ms Macklin will deliver their final report in November.

The premier admitted reforming the party would be a "painful process", but will lead to rank and file members having a greater say in Labor's future.

"What we'll have coming out of this is a better structure, one which is going to be fit for purpose for the future and one which will mean that we can get floods of people joining," Mr Andrews told reporters.

A motion put by the opposition in Victoria's upper house referring the scandal to Ombudsman Deborah Glass was passed on Wednesday, with the help of Labor and a swag of crossbenchers.

Leader of the government in the chamber Jaclyn Symes said the ombudsman may have to wait until the corruption watchdog and Victoria Police are finished investigating.

But Labor wouldn't oppose the motion because Ms Glass would be "able to consider the matters herself and form her own judgements".

Liberal MP David Davis said the ombudsman probe was needed as the scandal had "very serious ramifications for our democracy".

Mr Somyurek denies the allegations and wants police to investigate the legality of the recordings aired by Nine.

Mr Scott and Ms Kairouz vowed to clear their names and remain part of the Labor government.

Mr Andrews said he was confident nobody else in his team has been allegedly using taxpayer-funded staff to further political interests.

Australian Associated Press