A British newspaper released new details of its confrontation with the country’s intelligence service on Tuesday, saying it destroyed hard drives containing material leaked by Edward Snowden in order to insulate the former American intelligence worker from potential prosecution and to keep reporting on his leaks.

The Guardian said senior staffers shattered the electronics using angle grinders and drills in mid-July in a bid to avoid legal action or even a police raid that could halt its reporting or provide evidence for U.S. officials seeking to put Snowden behind bars.

“I didn’t want to get in that position,” editor Alan Rusbridger said in a video interview posted to the Guardian’s website. “Once it was obvious that they would be going to law, I would rather destroy the copy than hand it back to them or allow the courts to freeze our reporting.”

He said the paper has other copies of the same material located elsewhere.

Rusbridger spoke as disquiet continued to grow over the detention of Guardian journalist Glenn Greenwald’s partner, David Miranda, whose was held for nine hours at London’s Heathrow Airport on Sunday as he was ferrying material related to the Snowden story between filmmaker Laura Poitras in Germany and Brazil, where Greenwald is based.

Snowden’s leaks have served as the jumping off point for a series of stories about America’s globe-spanning surveillance program, including revelations that U.S. spies reach deep inside private companies to keep track of tens of millions’ of innocent Americans’ phone and Internet conversations with limited independent oversight. The stories have emboldened privacy activists and embarrassed President Barack Obama, who recently unveiled a slate of intelligence reforms intended to calm public concerns.

Legal commentators have questioned the legality of Miranda’s detention, which civil liberties group have decried as an abuse of power aimed at sabotaging Greenwald’s coverage.

“Miranda may have been carrying digital copies of secret documents made available to Laura Poitras and his partner Glenn Greenwald, but that does not make him a credible suspect in an investigation into terrorism,” broadcaster Bill Thompson said in an opinion piece posted by the Index on Censorship, a British free speech group.

The British government has declined to comment on the shattered hard drives, but it defended its decision to detain Miranda, saying it was right to stop anyone suspected of possessing “highly sensitive stolen information that would help terrorism.”

A law firm representing Miranda had begun legal action against the government, calling his detention unlawful and seeking assurances that British officials would not share the material seized from Miranda with anyone else. In a letter released to The Associated Press, London-based Bindmans called on the government to return a “mobile phone, laptop, memory sticks, smart-watch, DVDs and games consoles” taken from Miranda.

“These items contain sensitive, confidential journalistic material and should not have been seized.”

Experts have suggested the government’s case is dicey. The piece of legislation used to stop Miranda — Schedule 7 of the 2000 Terrorism Act — is especially contentious because it allows police to stop people for passing through airports for up to nine hours without suspicion they have committed an offense.

British legal blogger David Allen Green said Schedule 7 could only be used to determine whether person was a terrorist — and not, as he put it, “a fishing expedition for property.”

“If the questioning, detention, and search of Miranda was for a purpose other than to determine if he was a terrorist, then it was unlawful,” he said.

British Home Secretary Theresa May said it was right for the police to take action to protect the public.

“I think it’s absolutely right that if the police believe that if somebody is in possession of highly sensitive stolen information that could help terrorists, that could risk lives or lead to a potential loss of life, that the police are able to act, and that’s what the law enables them to do,” May said.

The government has claimed the decision to stop Miranda was made by police, although White House spokesman Josh Earnest said Monday that Britain had tipped off the U.S. government that Miranda would be detained. Prime Minister David Cameron’s office said Tuesday it had been “kept abreast of the operation,” but was not involved in the decision to stop Miranda.