Their arrest was lauded as a major milestone for Taskforce Maxima but now five people convicted under controversial Newman government association laws have successfully challenged the charges in court.
The five applicants petitioned the court for a ruling that were they were not "vicious lawless associates" under the Queensland government's controversial anti-association laws.
Defendants convicted under the Vicious Lawless Association Disestablishment Act can receive a higher penalty.
In March 2014, police executed search warrants on two properties in Willow Vale where they found two underground bunkers housing a huge haul of cannabis.
At the time Taskforce Maxima commander Detective Superintendent Michael Niland described it as a major milestone.
"This is the first time in Queensland the new Vicious Lawless Associate legislation has been used against a criminal gang other than an already declared Criminal Organisation (Criminal Motorcycle Gang)," he said.
"These are significant arrests and charges and it is our intention to take their criminal wealth away from them."
But on Tuesday, Justice Peter Lyons found the group were not "vicious lawless associates" under the terms of the legislation.
Justice Lyons found the group - Ben Andrew Hannan, Scott Alexander Hannan, Matthew Phillip Gillis, Nicholas Allan Murrell and Sarah McCarlie Muir Hannan - were not an association under the terms of the Vicious Lawless Association Disestablishment Act 2013 (Qld).
"The interest or purpose of Mr Ben Hannan was to make a profit from the production and sale of cannabis," Justice Lyons said.
"The interest or purpose of Sarah Hannan appears to have been to support Ben Hannan in that enterprise. While the other three applicants each had the purpose of earning money by assisting in the production and sale of cannabis, that was an individual purpose for each of them; and not a common interest or purpose."
Justice Lyons found the evidence revealed the applicants did not constitute an association for the purposes of the act and that none of them was a "vicious lawless associate".
The matter has been set for a mention on August 3 where further submissions will be made.
