The Guardian newspaper says British agents destroyed their newsroom hard drives after they began publishing revelations from National Security Agency leaker Edward Snowden.
In an opinion piece, Guardianeditor Alan Rusbridger claimed the hard drives were destroyed after weeks of pressure by British government officials.
He said the drives were torn apart in the basement of their office building as British intelligence agents looked on.
"One of the more bizarre moments in the Guardian's long history occurred with two GCHQ security experts overseeing the destruction of hard drives in the Guardian's basement just to make sure there was nothing in the mangled bits of metal which could possibly be of any interest to passing Chinese agents," Rusbridger wrote.
"'We can call off the black helicopters,' joked one staffer as we swept up the remains of a MacBook Pro," he said.
Rusbridger's op-ed comes in response to the detention of David Miranda, a partner of the reporter who broke the news about America's surveillance programs.