A New Zealand journalist has successfully stopped police viewing his computer records and notepads in a case which could have implications for the UK.
Nicky Hagar sued the New Zealand government and police after a raid on his home.
Police targeted him because he was given emails hacked from the computer of blogger Cameron Slater which were used as part of his book Dirty Politics. They revealed how government figures used Slater to damage their opponents.
Instead of tackling the issues raised by Hagar, police raided his house and seized his computers and various documents in a bid to uncover the source who had hacked Slater's computer.
Hagar sought judicial review and won meaning that police were not allowed to view his journalistic material, even though his source may have acted illegally.
Hagar told Press Gazette: "My case is just one of many around the world where governments have tried to identify confidential journalist sources.
"We can usefully learn from each other's experiences, especially between countries such as New Zealand and Britain that have similar legal systems.
"My court case drew heavily on British court cases and I hope that our victory here can be used to help protect sources in future British cases. It is the same fight, and the arguments and principles at stake are universal ones."
His lawyers successfully argued that the case had "grave implications" for democracy in New Zealand because the police actions damaged "the public's ability to receive information, through journalists, from people who are prepared to take great personal risks to expose wrongdoing and abuses of power".
Hagar's lawyers argued that police acted unlawfully by failing to take into account source confidentiality issues when they applied for their warrant. And they made the case with reference to international law, in particular the case of Goodwin versus UK Government. This was the 1996 case in which the European Court upheld the right of journalist Bill Goodwin not to disclose the identity of a source who had provided him with details of a confidential company document.
Goodwin, who now works for Computer Weekly, told Press Gazette: "This case extends the idea of protecting a source to police search warrants. It will definitely have influence on future court cases in the UK.
"It will mean that police will have an obligation to consider the impact on sources when they apply for search warrants. It will have influence on future UK court decisions."
In recent years UK police have made widespread use of their powers to identify confidential journalistic sources by: raiding journalists' homes, using production orders to obtain confidential emails from news organisations and secretly obtaining the telecoms data of news organisations and journalists.