Edward Snowden secured a job with a US government contractor for one reason alone - to obtain evidence of Washington's cyberspying networks, the South China Morning Post can reveal. For the first time, Snowden has admitted he sought a position at Booz Allen Hamilton so he could collect proof about the US National Security Agency's secret surveillance programmes ahead of planned leaks to the media. "My position with Booz Allen Hamilton granted me access to lists of machines all over the world the NSA hacked," he told the Post on June 12. "That is why I accepted that position about three months ago." During a live global online chat last week, Snowden also stated he took pay cuts "in the course of pursuing specific work". He said: "Booz was not the most I've been paid." His admission comes as US officials voiced anger at Hong Kong, and indirectly Beijing, after the whistle-blower was allowed to leave the city on Sunday. Snowden is understood to be heading for Ecuador to seek political asylum with the help of WikiLeaks, which claimed to have secured his safe passage to the South American country. Snowden, who arrived in Hong Kong on May 20, first contacted documentary maker Laura Poitras in January, claiming to have information about the intelligence community. But it was several months later before Snowden met Poitras and two British reporters in the city. He spent the time collecting a cache of classified documents as a computer systems administrator at Booz Allen Hamilton. In his interview with the Post , Snowden divulged information that he claimed showed hacking by the NSA into computers in Hong Kong and the mainland. "I did not release them earlier because I don't want to simply dump huge amounts of documents without regard to their content," he said. "I have to screen everything before releasing it to journalists." Asked if he specifically went to Booz Allen Hamilton to gather evidence of surveillance, he replied: "Correct on Booz." The documents he divulged to the Post were obtained at Booz Allen Hamilton in April, he said. He intends to leak more of those documents later. "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." Two days after Snowden broke cover in Hong Kong as the source of the NSA leaks, Booz Allen Hamilton sacked him.