South Korea's spy agency transferred large amounts of intelligence on North Korea to the U.S. Defense Intelligence Agency, an on-line whistle blower site claimed Saturday.

WikiLeaks said based on reports sent by the U.S. embassy in Seoul to the State Department dated July 9, 2007 that the South's National Intelligence Service handed over data collected through interviews with around 9,000 North Korean defectors.

The flow of information started in 1997 and ran through 2007 with NIS agents transferring intelligence they acquired on a regular basis to DIA agents in the country.

It said information provided touched on the integrity of the North Korean regime, possibility of its collapse, human rights abuses and other materials that could be used to prepare for emergency situations.

WikiLeaks added that included in the data sent to the U.S. agency that primarily handles military intelligence were views expressed by ordinary people of failed reform programs and how North Koreans obtain information about South Korean society.

Related to the claims, the NIS told Yonhap News Agency that it cannot verify if such a transfer took place.

Private experts, however, said that it is nothing out of the ordinary for Seoul to provide intelligence to its closest ally, especially since the South has the best access to so-called human intelligence. There are some 25,000 North Korean defectors in the South that can give first-hand testimonies to events taking place in the North.

They hinted that in exchange Washington probably provides the South with critical information collected by its own intelligence gathering assets. (Yonhap News)