The Guardian reports on the story, here:
'Downing Street and the Home Office are being challenged to answer in public claims that Russia and China have broken into the secret cache of Edward Snowden files and that British agents have had to be withdrawn from live operations as a consequence.
'The reports first appeared in the Sunday Times, which quoted anonymous senior officials in No 10, the Home Office and security services. The BBC also quoted an anonymous senior government source, who said agents had to be moved because Moscow gained access to classified information that reveals how they operate. ...
'[Eric King of Privacy International] added that if Downing Street and the Home Office believed that Russia and China had gained access to the Snowden documents, then why was the government not putting this out through official channels.
'He added: “Given Snowden is facing espionage charges in the US, you would have thought the British government would have provided them with this information.”'
The Guardian destroyed the Snowden hard drives in front of British security in July 2013 after the British government threatened to shut down the newspaper, as reported here:
'New video footage has been released for the first time of the moment Guardian editors destroyed computers used to store top-secret documents leaked by the NSA whistleblower Edward Snowden.
'Under the watchful gaze of two technicians from the British government spy agency GCHQ, the journalists took angle-grinders and drills to the internal components, rendering them useless and the information on them obliterated.'
The Guardian acknowledged at the time that the Snowden files exist in other jurisdictions:
'[The Guardian's] Rusbridger told government officials that destruction of the Snowden files would not stop the flow of intelligence-related stories since the documents existed in several jurisdictions. He explained that Glenn Greenwald, the Guardian US columnist who met Snowden in Hong Kong, had leaked material in Rio de Janeiro. There were further copies in America, he said.'