The Australian Workers' Union (AWU) served legal documents to Michaelia Cash's former chief of staff Ben Davies on Monday, as part of its challenge of the police raids on its offices last year.



BuzzFeed News revealed last month that the union hired private investigators to track down Davies in order to serve him with a subpoena to produce documents and give evidence in the Federal Court.

Davies' lawyers told the ABC that hiring the investigators was unnecessary. They claim he does not have any information relevant to the case.

The AWU launched its Federal Court challenge after BuzzFeed News revealed that Cash's office tipped off the media about the October 24, 2017 raids by the Australian Federal Police (AFP) on its Sydney and Melbourne offices.

The raids were part of an investigation by the Turnbull government-established watchdog, the Registered Organisations Commission (ROC), into donations made by the union over a decade ago, when it was led by current Labor leader Bill Shorten.



Cash denied five times in Senate Estimates last year that her office had any involvement with the media leak, before announcing her senior media adviser David De Garis had claimed responsibility and resigned. In February a journalist claimed they had received a phone call from then justice minister Michael Keenan's office informing them of the raids before they took place.

The union has also issued Federal Court subpoenas to produce documents and give evidence to four other people: Cash, De Garis, former Fair Work Ombudsman media officer Mark Lee and ROC official Chris Enright.

To date, Cash has not challenged the subpoena, but has publicly indicated she instructed her taxpayer-funded lawyers to do so.

The case has been delayed until the AFP's investigation into the "unauthorised disclosure of government information" is complete. It is currently slated for trial in February 2019.

The AFP told Senate Estimates last month that the investigation is not officially complete, but that it has provided a full brief of evidence to the Commonwealth Director of Public Prosecutions.



Internal AFP documents published by BuzzFeed News revealed the leak investigation was given the same priority as the investigation into the "liking" of a porn tweet by minister Greg Hunt's Twitter account. That six-month investigation found the minister's account was not hacked.

At the time of publishing Davies' lawyers had not responded to questions from BuzzFeed News.