BRITISH Prime Minister David Cameron has refused to comment on reports that the country's intelligence services intercepted communications by delegates attending two G20 meetings in 2009 in London.

"We never comment on security or intelligence issues and I am not about to start now. I don't make comments on security or intelligence issues - that would be breaking something that no government has previously done," Cameron told Sky News on Monday.

The revelations risked embarrassing Cameron as he prepared to host the G8 summit in Northern Ireland, where the recent discovery of electronic eavesdropping by the United States was likely to cause tension.

Computers and telephones at the G20 meetings were monitored, the Guardian newspaper reported online late on Sunday, citing US whistleblower Edward Snowden and documents seen by its reporters.

Snowden, a former US intelligence official, also revealed the existence of PRISM, a top-secret scheme run by the US government to intercept worldwide emails and track telephone calls.

The G20 summit in April 2009 and the finance ministers' meeting in September that year were hosted by Cameron's predecessor, Gordon Brown of the Labour Party.

Some G20 delegates were led to use internet cafes that had been set up to enable their messages to be tracked by Britain's Government Communications Headquarters (GCHQ), the communications arm of the intelligence services.

The initiative, which targeted countries including Turkey and South Africa, was to improve Britain's negotiating position during the summit, rather than address security concerns, the report said.

Originally published as Cameron refuses comment on G20 spy claims