LONDON, Nov 20 (Reuters) - Telecommunications firm Cable & Wireless helped Britain eavesdrop on millions of Internet users worldwide, Channel 4 reported on Thursday, citing previously secret documents leaked by a fugitive former U.S. National Security Agency contractor.
Cable & Wireless, which was bought by Vodafone in 2012, provided British spies with traffic from rival foreign communications companies, Britain's Channel 4 television said, citing documents stolen by Edward Snowden.
Channel 4 said Cable & Wireless gave Britain's GCHQ eavesdropping agency access by renting space on one of the arteries of global communications, a cable that runs to the southern English region of Cornwall.
The Channel 4 report, which was impossible to immediately verify given the secrecy of the surveillance programmes, said Cable & Wireless carried out surveillance on Internet traffic through its networks on behalf of British spies.
The documents cited in the report were not shown on Channel 4's web site. But previous disclosures by Snowden have illustrated the scale of U.S. and British eavesdropping on everything from phone calls and emails to Internet and social media.
Some telecommunications and Internet companies in Britain and the United States were asked or forced to cooperate with the eavesdropping programmes, according to previous media reports.
When asked for comment on the Channel 4 report, Vodafone said in a statement that it had examined the history of Cable & Wireless compliance and found no evidence that would substantiate the allegations.
"We have found no indication whatsoever of unlawful activity within Vodafone or Cable & Wireless and we do not recognise any of the UK intelligence agency programmes identified," it said in a statement. "Furthermore, Vodafone does not own or operate the cables referred to."
It added that national laws require it to disclose some information about its customers to law enforcement agencies or other government authorities when asked to do so.
In the wake of the Snowden revelations, GCHQ was accused by privacy groups and some lawmakers of illegally monitoring electronic communications.
British ministers denied any illegality and top spies dismissed suspicions of sinister intent, saying they sought only to defend the liberties of Western democracies. GCHQ declined to comment on the Channel 4 report.
Andrew Parker, director general of MI5, Britain's domestic security service, warned last year that the revelations from Snowden, who now lives in Moscow, were a gift to terrorists because they had exposed GCHQ's ability to track, listen and watch plotters. (Reporting by Guy Faulconbridge and Kate Holton; Editing by Mark Heinrich)