Government urged to respond to claims that Snowden files have been accessed by Russia and China

More questions than answers from The Sunday Times report, which suggests that MI6 agents had to be withdrawn from 'hostile countries'

The UK government has been urged to respond to claims that Russia and China have been given access to the cache of top-secret documents leaked by former NSA contractor Edward Snowden.

The claims were reported by The Sunday Times, who cited senior officials in Downing Street, the Home Office and the security services, while the BBC said it had also been briefed by a senior government official who wished to remain anonymous.

The reports suggested that the UK's overseas intelligence agency, MI6, had been forced to "pull agents out of live operations in hostile countries", as a result of Russia and China getting access to the documents.

But despite the fact that stories of this nature regularly cite anonymous sources, there is pressure from privacy campaigners for the UK government to be more open about this particular situation, particularly with national security at the forefront of the report.

"Looking at The Sunday Times, it asks more questions than it answers," Eric King, the deputy director of Privacy International told the Guardian.

He questioned why the government was not releasing the information that Russia and China had gained access to the Snowden documents through its official channels.

"Given Snowden is facing espionage charges in the US, you would have thought the British government would have provided them with this information," he said.

There are other questions remaining too, such as why would the government want to place information like this out in the public domain now? One suggestion is that it is in response to David Anderson's report on surveillance which was released last week, which criticised the existing legal framework for surveillance.

Shami Chakrabarti, director of Liberty, said: "Last week, David Anderson's thoughtful report called for urgent reform of snooping laws. That would not have been possible without Snowden's revelations. Days later, an ‘unnamed Home Office source' is accusing him of having blood on his hands. The timing of this exclusive story from the securocrats seems extremely convenient."

Other questions for the government remain: is there any evidence of Russia and China gaining access to these documents, and what is actually said in the documents – could it really be enough information for the UK to have to withdraw MI6 agents?

Both Downing Street and the intelligence agencies refused to comment.