Australia\'s richest person Gina Rinehart has lost a long-running legal bid to force a media group to hand over their source material in a messy dispute over her family\'s mining fortune. Rinehart had been trying to force West Australian Newspapers to surrender all letters, faxes, emails, legal advice, memos, text messages and recordings between their journalist Steve Pennells and her son, John Hancock. Hancock and his sister Bianca Rinehart are embroiled in acrimonious legal proceedings with their mother, an iron ore heiress with an estimated Aus$22 billion (US$20 billion) fortune, over a family trust established by their prospector grandfather Lang Hancock. Pennells published a series of exclusive articles over the imbroglio and Rinehart subpoenaed him and the West Australian newspaper to produce its source material in an almost two-year legal battle. But the state\'s Supreme Court tossed out Rinehart\'s application in a judgement late Tuesday by judge Janine Pritchard. \"WAN\'s application to set aside the subpoena should be upheld in part, on the ground that the subpoena is oppressive and constitutes an abuse of process,\" Pritchard said in her judgment. Editor Brett McCarthy said it was a win for the newspaper and for journalism, being the first test of Western Australia\'s new \"shield laws\" protecting journalists from revealing their sources. \"The judge carefully weighed up the rights of our journalist Steve Pennells to maintain a confidential source against the rights of a litigant to have that source revealed and found in our favour,\" said McCarthy. Australia\'s journalists\' union welcomed the decision and said it was \"outrageous that, even with shield laws in place, Steve Pennells was forced through a very lengthy, expensive and stressful series of court procedures before this decision reiterated the position of the law\". \"The court\'s decision underscores the need to acknowledge and respect journalist privilege in relation to the journalists\' ethical requirement to refuse to disclose their confidential sources,\" said union secretary Chris Warren. \"But it is a principle that still needs to be properly enshrined in (national) law.\" Another journalist, Fairfax\'s Adele Ferguson, is awaiting verdict on a similar bid for source material by Rinehart relating to her unauthorised biography about the outspoken mining baroness who made waves with a series of share splurges in media companies last year. \"I think it is a great win for journalism and press freedom,\" said Ferguson of the Pennells ruling. \"The judgment was strong and made it clear that sources should be protected and journalistic ethics respected.\"