The union claimed the referral from Senator Cash and her staff leaking news of the raids were proof that the probe was politically motivated, intended to "embarrass or politically harm" Mr Shorten, and was therefore unlawful. Loading But Justice Mordecai Bromberg dismissed the union's allegations on Friday and ruled the commissioner’s investigation was not politically motivated, and that the AWU had failed to demonstrate the decision to probe the union was influenced by Senator Cash’s referrals. "The contention [by AWU] was that concerns expressed and requests made by the minister in two letters forwarded to the commissioner by her had influenced the decision to investigate," Justice Bromberg said. "On the evidence, I have held that the AWU has not demonstrated that the minister’s communications to the commissioner were a material and operative reason for the commissioner’s decision to investigate.

"I have concluded that the evidence before the court does not establish that the decision made to conduct the investigation was made for the improper purpose contended for by the AWU." A spokesman for Senator Cash said the judgment cleared her of wrongdoing. "The AWU’s pursuit of the minister was always a political game," the spokesman said. "Despite the political attack by the AWU, the minister has been cleared of any political influence over the ROC’s decision." However, Justice Bromberg ruled the commissioner's decision to launch an investigation was invalid over a "jurisdictional" error and that a half-day hearing would be set to determine whether the search warrants were also invalid.

Loading Replay Replay video Play video Play video Justice Bromberg said the commission's probe of the unions was based on a "suspicion", which was not a reasonable ground for an investigation. "The commissioner did not proceed reasonably in forming the opinion or state of satisfaction he was required," Justice Bromberg said. "Having concluded that the decision to conduct the investigation is invalid in so far as the investigation concerns whether [certain sections] of the Registered Organisations Act has been contravened, I have given some consideration as to whether the search warrants are invalid. "I have concluded that that matter ... should be the subject of further submissions from the parties and a short further hearing."

Australian Federal Police raided the Melbourne and Sydney offices of the union on October 24, 2017 as part of the investigation into a 2006 GetUp donation and a $25,000 donation made in 2007-08 to Mr Shorten’s first parliamentary campaign for the seat of Maribyrnong. Loading Mr Shorten was AWU national secretary from 2001 until he entered politics in 2007, and was on the board of GetUp until early 2006. AWU donations to Labor campaigns in the federal seats of Stirling and Petrie were also under the commission's scrutiny. At an earlier hearing, Senator Cash told the court she found out about the AFP raids as they unfolded live on television.

Ben Davies, the senator's then chief-of-staff, and David De Garis, her then media adviser, have since been implicated in the leaks to the media, as has Michael Tetlow, who at the time worked for the-then justice minister Michael Keenan. The investigation was probing donations made by AWU to GetUp and Labor campaigns while Bill Shorten was union leaer. Credit:Alex Ellinghausen Mr Shorten blasted the commission's investigation as a waste of taxpayers' money. "The witch-hunt cost millions and the government cowboys running it did not even stop to check if their investigation was legal," he wrote on Twitter. "What a waste of taxpayers' money when so many Australian families are doing it tough."