Downing Street believes that Russian and Chinese intelligence agencies have used documents from whistleblower Edward Snowden to identify British and US secret agents, according to a report in the Sunday Times.
The newspaper says MI6, Britain’s Secret Intelligence Service, has withdrawn agents from overseas operations because Russian security services had broken into encrypted files held by American computer analyst Snowden.
Snowden provided the Guardian with top secret documents from the US National Security Agency (NSA), which revealed that western intelligence agencies had been undertaking mass surveillance of phone and internet use.
He fled to Hong Kong, then to Moscow, and the Sunday Times claims that both Chinese and Russian security officials gained access to his files as a result.
The files held by Snowden were encrypted, but now British officials believe both countries have hacked into the files, according to the report.
The newspaper quotes a series of anonymous sources from Downing Street, the Home Office and British intelligence saying that the documents contained intelligence techniques and information that would enable foreign powers to identify British and American spies.