US and South Korean intelligence agencies are sitting on a huge archive recording torture, starvation and gross human rights abuses in North Korea. The files would be of great value to a United Nations investigation into crimes against humanity by the Pyongyang regime.

Previously unreported US embassy cables released by WikiLeaks show the South Korean National Intelligence Service and the US Defence Intelligence Agency hold an ''enormous trove'' of information obtained from the debriefing of thousands of North Korean defectors.

Military state: North Korean soldiers march past statues of the country's two former leaders. Credit:Reuters/Kyodo

The US embassy in Seoul said this ''untapped source'' is a ''massive collection of contemporaneous, first-hand testimony [that] would be directly relevant to … building a record of accountability for human rights violations''.

US diplomats reported to Washington that just four randomly selected files contained testimony of forced labour, the inducement of abortions, torture by electric shock, people trafficking and efforts to disguise the diversion to the North Korean military of humanitarian aid.