A Japanese daily says that South and North Korean officials held secret contacts in the fall of last year.

The Asahi Shimbun daily cited a South Korean source as saying that the two sides discussed keeping inter-Korean ties separate from the nuclear issue.

But the paper says the contacts failed to result in any progress, as North Korea's shelling of the South's Yeonpyeong Island immediately followed.

Asahi says that during the meeting, the South requested the North take responsible measures regarding the sinking of the South's "Cheonan" warship but that Pyongyang denied any involvement in the incident.