“This review has found a small number of possible breaches of the party’s rules around payment of other members’ fees,” Mr McQuestin said.
“Each of the members concerned has been contacted to verify the position, ahead of action potentially being taken to cease their membership if the party’s rules have been breached.
“The Liberal Party takes the integrity of our membership procedures and internal democratic processes very seriously.”
Under Liberal and Labor Party rules, branch stacking and paying for other people’s membership fees are banned.
The Victorian Liberals have for years been dogged by allegations of branch stacking, in which the religious right has been accused of stacking branches with Mormons and Catholic groups in a drive to preselect more conservative candidates.
Senior Liberal frontbench MP Georgie Crozier said on Sunday that she had “full faith” Mr McQuestin would undertake a thorough investigation.
“I’ve got full faith in the party to absolutely undertake what needs to be done, and the state director in his role in what he is doing, in jumping on this very serious issue,” Ms Crozier said.
Ms Crozier was pressed several times on whether she was confident no senior Liberal MPs would be implicated in the internal investigation, but would not comment.
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“What I am pleased about is that the state director is jumping on this issue very quickly,” she said.
“Unlike the Labor Party, where we’ve seen a minister and his ministerial staff involved in branch stacking, our party is dealing with it and that’s a very good thing.
“It’s in stark contrast to how the Labor Party operates.”
An earlier version of this story quoted a federal MP. Those comments have been removed.
Sumeyya is a state political reporter for The Age.