NSA whistle-blower Edward Snowden began downloading documents about secret U.S. government surveillance programs while employed by Dell in April 2012, according to a Reuters report.

The former intelligence contractor began working at Dell in 2009 as a contractor at a National Security Agency facility in Japan. While employed at Dell, Snowden left an electronic trail that indicates he downloaded documents regarding electronic surveillance programs run by the NSA and Britain's Government Communications Headquarters, officials and sources close to the matter told Reuters.

Some of the documents Snowden reportedly accessed related to NSA data collection of Internet traffic and other communications from fiber-optic cables, including transoceanic cables, the sources said.

A Dell representative declined to comment on the report.

Snowden, who has been granted asylum in Russia, is wanted by the U.S. for leaking top-secret documents to the media about the NSA's surveillance practices. The NSA and the Obama administration have said the goals of the surveillance programs have been to track down foreign terrorists and terrorist threats.

The U.S. government has charged Snowden, 30, with espionage, theft, and conversion of government property. Since the leak, the U.S. government has revoked Snowden's passport and is working to extradite him back to the states.

Snowden has said that he left Dell earlier this year for a job at Booz Allen Hamilton to gain access to more classified documents regarding the NSA programs. Snowden's brief tenure at Booz Allen Hamilton ended in June, when he fled to Hong Kong with top-secret documents he leaked to the media.

In addition to the documents about surveillance programs, Snowden reportedly has very sensitive "blueprints" describing how the NSA operates. The former contractor has "literally thousands of documents" that constitute "basically the instruction manual for how the NSA is built" that could aid in duplicating or evading NSA surveillance tactics, The Guardian's Glenn Greenwald told the Associated Press last month.