The partner of Guardian journalist Glenn Greenwald is taking legal action against the UK over his detention at London's Heathrow Airport, The BBC reports.
Miranda, 28, was detained for nine hours on Sunday after he spent a week in Berlin visiting journalist Laura Poitras, who has been working with Greenwald to publish stories relating to materials leaked to them by former NSA contractor Edward Snowden.
The detention occurred under Section 7 of the very broad British Terrorism Act, which allows the authorities to detain someone for up to nine hours to conduct questioning and search personal items to determine possible ties to terrorism.
Authorities questioned Miranda and seized all of his electronic equipment, including encrypted thumb drives that Greenwald said involved his work with Poitras.
Miranda's lawyers are trying to prevent the police from examining the confiscated data.
It's unclear what Miranda's role is in the situation. The trip, paid for by the Guardian, involved "ferrying materials" between Greenwald and Poitras.
The New York Times reported that Miranda was carrying classified documents given to the journalists by Snowden, but Greenwald said he only told the paper that the material was relating to their NSA work.
Miranda, a Brazilian, told the Guardian: "I don't have a role. I don't look at documents. I don't even know if it was documents that I was carrying."
But later Rusbridger, the Guardian editor, wrote that Miranda "is not a journalist, but he still plays a valuable role in helping his partner do his journalistic work."
Former senior U.S. intelligence analyst Joshua Foust wrote that while the nine hours of detainment seemed excessive, "it’s a bit difficult to see why anyone would be surprised that he would be at the very least questioned by British authorities."
Greenwald called the detainment a failed attempt at intimidation while Michael Mansfield, one of Britain's leading human rights lawyers, called it "sheer unadulterated state oppression."
The UK government defended the detention, saying police must act if they think someone has "stolen information that would help terrorism."
On Monday Greenwald said that everything Miranda was carrying "was heavily encrypted, and I’m not worried at all that they can break that.”
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