SEOUL - A third man has been arrested over a plot to assassinate a top ranking defector from North Korea, a report said Saturday.

The man, whose family name is Han, was a former North Korean agent who has been living in South Korea since the 1960s, Yonhap news agency said, quoting prosecutors.

His arrest came after a South Korean court on Thursday handed 10-year prison sentences to two North Korean agents who posed as fugitives from the communist state in a bid to assassinate Hwang Jang-Yop.

Han was charged with seeking to trace Hwang`s address in a plot to assassinate him, Yonhap said.

Han was recruited said to have been recruited by North Korean agents in 2000, who helped him reunite his family members living in the North.

North Korea has denied involvement in the bid to assassinate Hwang, accusing Seoul of inventing the story to fuel tension.

Hwang, architect of the Pyongyang regime`s ideology of "juche" or self-reliance, was once secretary of the ruling Workers` Party and a tutor to current leader Kim Jong-Il.

He defected in 1997 during a visit to Beijing, becoming the highest-ranking official to flee the hardline state, and now lives under guard in the South at a secret address.

The North has branded Hwang as "traitor".

Tensions are high on the Korean peninsula after the South accused the North of torpeding one of its warships in March with the death of 46 sailors.

BDST: 12:45 HRS, July 3, 2010