Lawyers were seeking to prevent access to data seized during David Miranda's detention and judges ruled that the UK government and police are exempt from "inspecting, copying or sharing" the data, except for national security purposes.
Miranda, the Brazilian partner of US journalist Glenn Greenwald, was held for nine hours under anti-terror laws at Heathrow airport on Sunday in connection with classified data of American National Security Agency (NSA) leaked to the 'Guardian' newspaper.
Matthew Ryder QC, who is representing Miranda, told the High Court today they wanted a 14-day freeze on the inspection of his phone and computer. He also wanted police to reveal with whom they may have shared information taken from his client.
Ryder told Lord Justice Beatson and Justice Kenneth Parker that Miranda was questioned and property in his possession was seized "under threat of criminal prosecution in a coercive use of Schedule 7 which was unlawful".
More From This Section
"The purpose of these proceedings is to protect the confidentiality of the sensitive journalistic material that was seized from the claimant. Confidentiality, once lost, can clearly never be restored," she said.
There will be a full hearing on the question of continuing police inspections on August 30.
The High Court will then further consider Miranda's application for an interim injunction to stop examination "until the legality of that seizure has been determined by this court".
The incident has sparked international outrage as Greenwald has been reporting extensively on American and British surveillance programmes for the 'Guardian', based on leaks from US whistleblower Snowden.
The former contractor with the NSA in America has been granted temporary asylum in Russia.