The incident was apparently part of an effort to keep the leaks out of the hands of Chinese spies, according to reports.

Rusbridger said the GCHQ security experts destroyed the hard drives “just to make sure there was nothing in the mangled bits of metals which could possibly be of any interest to passing Chinese agents.”

Snowden, who leaked top-secret details about a National Security Agency surveillance program that has sparked an international debate over government spying, was granted temporary asylum by the Russian government earlier this month. The U.S. government wants the leaker sent back to face trial on espionage charges.

Rusbridger called the shredding incident “one of the more bizarre moments in the Guardian's long history.”

It is unclear when the event occurred, although Rusbridger indicated it happened in the past month, after weeks of pressure by British officials,