British newspaper The Guardian says documents leaked by a former U.S. intelligence contractor show that Britain spied on diplomats attending the 2009 Group of 20 summit in London.
In a report published Monday, The Guardian said Britain's eavesdropping agency, the General Communications Headquarters (GCHQ), hacked into the phones and computers of Turkish and South African delegates at the summit. It said the GCHQ also tricked some G-20 delegates into using Internet cafes that it secretly modified to intercept diplomatic communications.
The newspaper published redacted versions of some of the documents it said were leaked by Edward Snowden, the former U.S. National Security Agency contractor who exposed some U.S. surveillance operations earlier this month after fleeing to Hong Kong.
The authenticity of the documents could not be immediately confirmed. Their release coincided with Britain hosting the first day of a Group of Eight industrialized nations summit in Northern Ireland.
British Prime Minister David Cameron refused to confirm or deny The Guardian report, saying that commenting on security issues would be "breaking something that no [British] government has previously done."
It is not clear whether Snowden had access to British intelligence information. But a British academic who wrote a history of the GCHQ, Richard Aldrich, told the Associated Press that the British agency has collaborated closely with the NSA.
In another development, a Chinese Foreign Ministry spokeswoman said U.S. authorities should pay attention to international concerns about NSA surveillance operations and provide what she called a "necessary explanation." It was the first comment by a Chinese official on the NSA leaks since Snowden sought refuge in the autonomous Chinese territory of Hong Kong last month.
Speaking Monday, Chinese Foreign Ministry spokeswoman Hua Chunying also denied that Snowden has spied for China, calling the suggestion "complete nonsense." Former U.S. Vice President Dick Cheney said Sunday he is concerned that Snowden is cooperating with Chinese authorities.
Snowden remains in hiding in Hong Kong, but has given interviews to several newspapers. He has vowed to use Hong Kong's British-rooted legal system to fight any attempt to extradite him to the United States. The U.S. Federal Bureau of Investigation has said Snowden is under criminal investigation, though it has not filed any charges against him or asked for his extradition.