A WA Supreme Court judge has reserved a decision on the fate of subpoenas compelling award-winning journalist Steve Pennells to reveal sources for articles that Hancock Prospecting's lawyers claim are nothing more than Rinehart family "gossip".
Lawyers for Pennells and The West Australian newspaper on Tuesday laid out an argument, centred on oppression and abuse of process, for resisting subpoenas served on them by Hancock in early 2012.
Pennells' lawyers say honouring the subpoenas and producing documents would breach a fundamental "tenet of journalism".
The subpoenas relate to a New South Wales-based arbitration between Mrs Rinehart's Hancock Prospecting and her estranged son, John Hancock.
They compel The West Australian to hand over all notes and recordings concerning Mrs Rinehart, Mr Hancock, Hancock Prospecting and the billion-dollar trust at the heart of the mining magnate's public family feud.
WA's media shield laws do not expressly cover pre-trial proceedings, like an arbitration, but Robert Anderson, QC, for the paper, said they indirectly played into a broader argument about the subpoenas being oppressive. "The shield laws here have a paramount importance that should not be ignored," he told the court.
Mr Anderson said it was "telling" that Hancock had not tried to get the relevant documents from Mr Hancock, who was a party to the proceedings.
Instead the company had continued with the subpoenas against journalists, which now include BusinessDay columnist Adele Ferguson, who wrote an unauthorised biography of Ms Rinehart.
Mrs Rinehart is the largest shareholder of Fairfax Media, the owner of this newspaper.