The Labor Party is preparing to expel more than 10 per cent of its Victorian membership.

At least 1800 members will be dropped in a major branch-stacking purge.

It comes after reports that Labor powerbrokers have organised large numbers of people, often from specific ethnic groups, to join the party and influence key ALP processes such as pre-selections for federal and state seats.

Some of the members did not know they had joined the Labor Party, as they were signed up by someone else, while other memberships will be dropped because the person behind them does not exist.

Former Labor staffer Nick McLennan will be kicked out, after working with former minister and powerbroker Adem Somyurek to pay for dozens of party memberships for people who had no desire to join the ALP.

The announcement comes as an investigation led by former Labor premier Steve Bracks and former federal MP Jenny Macklin nears completion.

Mr Bracks and Ms Macklin are working with auditors from Deloitte and lawyers from Holding Redlich to identify suspect members.

More than 1,800 financial and non-financial members have been identified and are earmarked for expulsion in coming weeks.

However, insiders have told reporters that the purge does not go far enough, because Mr Somyurek's ‘Moderates’ faction has about 4,000 members.

The former powerbroker has previously boasted that he controlled two-thirds of the 14,000-strong Victorian branch.

It is alleged that ‘Somyurek acolytes’ will remain in charge of same stacked branches.

Others have warned that purge may be meaningless if staffers are expelled but the ministers and MPs directing them remain in the party.