UK under pressure to respond to latest Edward Snowden claims

Sunday Times says Downing Street believes Russia and China have hacked into American whistleblower's files, endangering US and British agents

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that Russia and China have broken into the secret cache of Edward Snowden files and that British agents have had to be withdrawn from live operations as a consequence.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.