LONDON — The British government fears that material seized from the partner of a Guardian journalist could compromise counterterrorism operations, a senior national security adviser said Friday, arguing that intelligence agents in the field could be exposed as a result of the data.
It was the first time the government has offered specific reasons why security services and police are so concerned about material seized from David Miranda — the partner of Guardian journalist Glenn Greenwald.
Miranda was detained at Heathrow Airport and questioned for nearly nine hours under terrorism legislation earlier this month, but the government had earlier said only that it required access to the files on national security grounds.
Greenwald has written stories based on material leaked by former US National Security Agency contractor Edward Snowden. Miranda, a 28-year-old university student, was traveling home to Brazil after visiting Germany, where he met with Laura Poitras, a US filmmaker who has worked with Greenwald on the NSA stories.
Oliver Robbins offered a sweeping view of the government concerns before Britain’s High Court, saying the 58,000 classified UK documents are ‘‘highly likely’’ to describe techniques used in counterterror operations and could reveal the identities of UK intelligence officers abroad.
‘‘It would cause real harm to the work of the UK’s national security and intelligence agencies if an intelligence officer were to have his or her identity disclosed on anything other than an authorized and limited basis,’’ Robbins said in the statement dated this week ahead of a Friday hearing.
Guardian editor-in-chief Alan Rusbridger dismissed the statement as containing ‘‘unsubstantiated and inaccurate claims,’’ and questioned the danger, arguing that the government had done little to address the issue before Miranda’s detention.
‘‘The way the government has behaved over the past three months belies the picture of urgency and crisis they have painted,’’ Rusbridger said. ‘‘The government claims that they have at all times acted with the utmost urgency because of what they believed to be a grave threat to national security. However, their behavior since early June — when the Guardian’s first Snowden articles were published — belies these claims.’’
The statement came as the Guardian and the government agreed to allow the authorities to keep sifting through documents as long as it was on national security grounds. But Friday’s decision expanded that agreement, allowing the material to also be examined for ‘‘specified criminal grounds.’’ The government revealed the criminal investigation into Snowden’s leak of classified material to the Guardian during a court hearing last week.
The agreement came after the Guardian unsuccessfully sued last week to stop police from combing through digital material seized from Miranda.