South Korean intelligence authorities say a North Korean defector who was sent to the South as a spy turned himself in last June.

The National Intelligence Service (NIS) said Thursday that it referred the man, identified only by his surname Lee, to the prosecution in July for further investigations on his apparent violation of the National Security Law.

The NIS said the 28-year-old Lee, who had defected to the South through China last January, was caught by a North Korean border guard while trying to sneak back into the North to meet his family in April. Lee, a former staff sergeant with a North Korean border guard unit, had then reported on his activities in the South to a high-ranking security official of North Korea's border guard.

The NIS said Lee was subsequently dispatched back to the South after receiving ten days of espionage training in the northwestern border town of Shinuiju in May. Lee was reportedly ordered by North Korean authorities to join organizations of North Korean defectors and to return to the North with evidence of his activities, such as a membership certificate.

But the intelligence agency says it didn't find any evidence that Lee had engaged in espionage activities since his return to the South on May 19th and that Lee turned himself in early June after an apparent change of heart.

Lee took refuge in the South Korean consulate in Beijing in November, 2002 and was allowed to travel to Seoul for asylum in the South two months later.