Victoria's most powerful bikie clubs have been weakened by the departures of senior members as police turn the screws tighter on them.
The Hells Angels, Comancheros and Bandidos have all lost at least one senior member in just over six months, some handing in their patches while waiting for courts to rule on their fates.
The Rebels have been stung by an unprecedented Australian Crime Commission operation, the largest national operation to tackle a bikie club.
The leadership vacuum may lead to power struggles within clubs, which ACC chief executive Paul Jevtovic said operated under a "militaristic hierarchy". Police also fear that new conflicts could be sparked as rivals look to exploit weaknesses.
A bikie expert within law enforcement said that, while bikie clubs were fairly stable internally with replacements for leadership positions generally waiting in the wings, there was no telling how rival clubs may react.
"It's not like there's blood in the water and all the sharks smell it," the expert said.
"Other clubs have their own circumstances to consider, but there's always going to be people who want to exploit a weakness."
The expert said the high-disruption model used by police had worked, but would never be the only way to break bikie clubs.
Victoria Police launched the largest operation targeting a bikie club last year when they raided dozens of properties linked to the Hells Angels. The Comancheros were hit in another huge raid earlier this year.
The Echo taskforce declined to comment on the success of the raids, which led to charges against several senior members and dampened a feud between the Hells Angels and Comancheros.
The expert said the disruption method had shown results but was "only one tool in the toolkit". He said other factors such as a solid legislative framework and sound intelligence could be just as important.
The Mongols, considered the most powerful club outside the "big four" in Victoria, also have lost a senior member this year, with state president Frank Dieni reportedly turfed out.