A South Korean activist who claimed have been tortured by Chinese authorities while under detention is considering bringing his case to the International Criminal Court, his close aides said Sunday.

  Kim Young-hwan and three other activists trying to help North Korean refugees in China were arrested in late March and accused of endangering Beijing's national security.

  After being deported to South Korea last week, Kim said he was physically abused and criticized the Seoul government for taking a cautious approach to his claims. His colleagues told local media Kim was subjected to electric shocks and other abuses during his first month of detention.

   Beijing denies the allegation of torture.

   "What we can do is file a petition with the International Criminal Court about China's torture of Kim," said a Korean activist who worked for a civilian committee calling for Kim's release. "We also have to think about lawsuits in China."

   The official said Kim does not want diplomatic conflict between South Korea and China nor wants to put China in trouble in the international society over the matter, but is considering the petition as a way to stop torture in the Asian giant.

   If Beijing apologizes and promises to take measures to prevent recurrences of such incidents, the committee will not appeal the case to the international court, the activist said.

   "However, we will mobilize all possible methods if China takes ambiguous attitude like now," he said, asking for anonymity due to the sensitivity of the issue.

   On Friday, South Korean Foreign Minister Kim Sung-hwan said he would press China to conduct a thorough investigation into the case.

   The 49-year-old Kim is the former leader of an underground leftist party who met the then-North Korean leader Kim Il-Sung in Pyongyang in 1991. He later became a fierce critic of the regime and now works for a Seoul-based rights group.