The journalist who broke the story about an intelligence leaker says he has even more damaging information about US spying activities. He said this would be released if something were to happen to Edward Snowden.

Glenn Greenwald, a journalist with Britain's Guardian newspaper, which first published Snowden's revelations, told Argentina's La Nacion that the former National Security Agency contractor and Central Intelligence Agency employee had so far elected to withhold much of the information he has.

"Snowden has enough information to cause harm to the US government in a single minute than any other person has ever had," Greenwald said in an interview in Rio de Janeiro published in the Saturday edition of the paper.  

"The US government should be on its knees every day begging that nothing happen to Snowden, because if something does happen to him, all the information will be revealed and it could be its worst nightmare," Greenwald added.

He also said among the documents Snowden had hid away in several different locations were some that detail how US spy programs conduct surveillance in Latin America.

"One way of intercepting communications is through a telephone company in the United States that has contracts with telecommunications companies in most Latin American countries," Greenwald said, without naming the company.

Stranded in Sheremetyvo

Snowden, 30, has been stranded in the transit area of one of Moscow's international airports since he left Hong Kong three weeks ago. It was while he was in Hong Kong that the Guardian first published his revelations.

Since then, US authorities have been seeking to get Snowden extradited so that he can be put on trial on espionage charges.

On Friday, Snowden told activists who visited him at Sheremetyvo Airport that he planned to apply for temporary asylum in Russia until it was safe for him to travel on to a permanent destination in Latin America.

On Saturday, Russian authorities said that they had not yet received such an application from Snowden. Meanwhile, Bolivian President Evo Morales reiterated his offer of asylum to Snowden while at the same time pledging that La Paz would adhere to all "diplomatic norms and international accords."

pfd/mkg (AFP, dpa, Reuters)