The partner of a Guardian journalist held for nine hours at Heathrow under anti-terror laws has urged High Court judges to rule that his detention was unlawful and breached his fundamental right to freedom of expression.
Brazilian David Miranda lives with journalist Glenn Greenwald, who exposed secret information on US surveillance leaked by whistle-blower Edward Snowden.
On Sunday 18 August he was in transit from Germany to Brazil when he was stopped at the airport, detained, questioned and searched by police under Schedule 7 of the Terrorism Act 2000.
Miranda had nine items, including his laptop, mobile phone, memory cards and DVDs, taken from him while detained.
His lawyers are challenging the use of the counter-terrorism powers at a two-day hearing in a packed courtroom in London before Lord Justice Laws, Mr Justice Ouseley and Mr Justice Openshaw.
Matthew Ryder QC, for Miranda, told the judges: "This claim is about the use of counter-terrorism powers, that can only be used at ports and airports, to seize journalistic material."
They heard argument that the powers in Miranda's case were "exercised for an improper purpose" – that the "dominant purpose" of the examining officers was not to determine whether he was a person involved in the commission, instigation or preparation of acts of terrorism, but to "assist the Security Service in accessing material in the claimant's possession".
Exercise of the powers was also unlawful, it was submitted, as it was a "disproportionate interference with his right to freedom of expression".
Ryder said the background to the legal action taken by Mr Miranda, the "spouse" of Greenwald, concerned material obtained by former US National Security Agency (NSA) contractor Snowden.
Since June, articles based on some of the Snowden material had been published by the Guardian and other highly-respected news publications, and one of the leading figures in writing those articles was Greenwald.
The QC said articles based on the material "have resulted in global interest" at the highest level and had started an international debate.
He told the court that at the relevant time Greenwald was working for the Guardian and Miranda was "assisting Mr Greenwald's journalistic work"
High Court judges have already ruled that the material seized from him could only be examined for national security purposes and the protection of the public, and no other.
The judicial review action is being contested by the Home Secretary and the Metropolitan Police.
Ryder said: "The exceptional nature of this case insofar as it involves the use of Schedule 7 powers to obtain highly controversial journalistic material, should not be underestimated."
The use of the power to take journalistic material from 28-year-old Miranda "appears to be unprecedented".
The QC argued that use of Schedule 7 measures against him was "not proportionate and in breach of his right to freedom of expression".
In written submissions before the judges opposing Miranda's claim, Steven Kovats QC emphasised on behalf of the Home Secretary that "disclosure of all the material stolen by Mr Snowden would be gravely damaging to the national security of the United Kingdom" and that "such disclosure would endanger lives".
The Home Secretary "pursuant to her duty to protect national security, had a duty to act against that risk".
Kovats argued that her national security duty to establish the nature of Miranda's activity was "consistent" with use by the police of
If publication of material obtained by Snowden was capable of being an act of terrorism – and the Home Secretary "submits that it is" – then "seeking to establish the nature of the claimant's activity" was both meeting the Home Secretary's national security duty and discharging the police's Schedule 7 function "of seeking to determine whether the claimant was or appeared to be a person who was or had been concerned in the commission, preparation or instigation of acts of terrorism".
A coalition of 10 media and free speech organisations have intervened in the case to express their concerns about the use of anti-terror powers against journalists.
Among those supporting Miranda is the Index on Censorship. Online Editor Sean Gallagher said after the case: “The Terrorism Act should be used to counter terrorism not to undermine investigative journalism into stories that are in the public interest, such as the ongoing revelations about mass surveillance by The Guardian and David Miranda’s partner, Glenn Greenwald. Misusing counter terrorism laws in this way is an attack on the free expression rights of journalists and their sources.”
The hearing continues tomorrow.