New Zealand has spied on about 20 countries, including trading partners Japan and China, as part of cooperation with the U.S. National Security Agency, according to documents released Wednesday.

The latest documents released by fugitive former NSA contractor Edward Snowden show that New Zealand's spy agency collects data on communications from about 20 nations, including Japan, China, North Korea and Iran, many of whom are close trading partners, and shares this information with Washington and other international allies.

The intelligence gathered by the Government Communications Security Bureau (GCSB) was passed on to the NSA and intelligence agencies in Australia, Britain and Canada, which along with New Zealand are members of the "Five Eyes" surveillance network, according to the documents dated April 2013.