A South Korean activist detained and allegedly tortured in China for helping North Korean refugees said Seoul should have taken a tougher stance with Beijing to win his freedom instead of relying on "quiet diplomacy."
Kim Young Hwan said the torture exposes a "serious flaw" in relations between Seoul and Beijing.
"I hope my case will help reduce the torture of political prisoners in China," he told reporters, calling for international support.
"The harsh treatment I have undergone in China is not a simple matter involving two countries but one that requires attention, criticism and help from the international community."
Kim was arrested on March 29 along with three other activists trying to help refugees who had fled North Korea for China. They were deported on July 20.
He said Chinese agents beat him, stopped him from sleeping for days and tortured him with electric shocks to collect information on activities by his group and Chinese helpers. He also accused Beijing of cooperating with Pyongyang to destroy his network in China and North Korea.
South Korea's foreign ministry, which has been under fire for alleged inaction in the case, has urged Beijing to launch a thorough investigation.
China last week rejected Kim's allegations as groundless.