A former North Korean agent - who claimed she bombed a South Korean airliner in 1987 on orders from Kim Jong-Il - says she believes the North's leader also ordered the sinking of a South Korean warship in March.

Kim Hyun-Hee, who was sentenced to death but later pardoned for her role in blowing up the plane with the loss of 115 lives, was quoted by the Monthly Chosun, a magazine published by Chosun Ilbo newspaper.

Former North Korean agent Kim Hyun-Hee. Credit:AFP

"No big incidents like this can happen without informing Kim Jong-Il," the ex-agent, who now lives under guard in South Korea, was quoted as saying.

"Although the planning and preparation would have been done by the military, final confirmation must come from Kim."