A North Korean crossed the sea border to South Korea on a raft late last month in a solo defection bid, according to a report released on Tuesday.
Yonhap news agency quoted a government source as saying that the man appeared to have left Kaemori in the North's southwestern province of Hwanghae.
The man was spotted aboard a rubber raft by the South's navy around 3am on October 30, the source was quoted as saying.
He had drifted to near the South's Yeonpyeong island, close to the disputed Yellow Sea border.
A Joint Chiefs of Staff spokesman declined to comment on the report.
Kaemori is the site of a North Korean artillery base which shelled Yeonpyeong in November last year and killed two civilians and two Marines.
At about the same time on October 30 a group of 21 North Koreans were found adrift aboard a small wooden boat off Socheong island in the Yellow Sea. They were taken to the western port of Incheon for questioning.
Hundreds of North Koreans flee hunger and repression in their isolated communist homeland each year. They mostly cross the land border to China, but the latest reported case would be the fifth seaborne arrival this year.
Source: AFP Asian Edition