PYONGYANG - The Democratic People's Republic of Korea (DPRK) alleged Thursday it had arrested a South Korean spy here and an investigation was underway.

A Ministry of State Security spokesman told the official news agency KCNA that a person, who it did not identify, had confessed to being an agent with South Korea's intelligence service.

"He confessed he is a South Korean who intruded into Pyongyang after illegally entering the DPRK from a third country," the spokesman said.

He was engaged in anti-DPRK espionage and plotting activities against the state in a third country bordering DPRK for nearly six years, while disguising himself as a religious devotee, KCNA said.

He entered the DPRK to rally dishonest elements and use them for undermining the stability of the country's social system, which fully proved "to what extent the puppet group of conservatives has reached in its anti-DPRK moves," the report said.