Edward Snowden has admitted he deliberately went to work for the US intelligence contractor Booz Allen Hamilton in order to harvest highly classified evidence of the National Security Agency (NSA) surveillance programs that he hoped to expose.

"My position with Booz Allen Hamilton granted me access to lists of machines all over the world the NSA hacked. That is why I accepted that position about three months ago," he told Hong Kong's South China Morning Post during an interview on June 12 that was published on Tuesday.

Asked if his decision to take the job had been a calculated move designed to give him access to secret information, Mr Snowden reportedly replied: "Correct on Booz."

Snowden, whose exact location was unknown on Tuesday morning, flew out of Hong Kong on Sunday and has reportedly requested asylum in Ecuador. He had been expected to fly from Russia to Cuba on Monday afternoon but as the Aeroflot plane prepared to take off from Moscow's international airport journalists who had boarded the flight found his seat empty.

In new extracts from his June 12 interview with the South China Morning Post Mr Snowden said he would continue to leak his findings to journalists around the world.

"If I have time to go through this information, I would like to make it available to journalists in each country to make their own assessment, independent of my bias, as to whether or not the knowledge of US network operations against their people should be published."

Snowden's admission was made public as new details emerged about his final hours in Hong Kong, where he had been in hiding since May 20.

According to an account in the New York Times, Mr Snowden plotted his escape from the former British colony over pizza and Pepsi at the home of one local supporter.

Albert Ho, a local pro-democracy campaigner and lawmaker, who was present at the dinner told the New York Times: "He believed he was doing the right thing, serving the people. Certainly he is not a spy for anybody Russia, China." Mr Snowden's decision to leave Hong Kong reportedly came after an "intermediary" from the Hong Kong government informed him that authorities could not guarantee he would not be jailed while awaiting trial.