A wrenching film about the human rights abuses in North Korea had its premiere in Seoul yesterday, but the man whose personal tragedy formed the basis of much of its plot remains so traumatised that he refuses to watch it.

Crossing stars Cha In-pyo, one of Asia's top actors, as a North Korean miner whose undernourished, pregnant wife contracts tuberculosis.

With no medicine available in the impoverished nation, Cha's character leaves his wife and 11-year-old son to travel to China to earn money for medicine. While he is away his wife dies.

His starving son attempts to escape to China but is captured and placed in a re-education camp, where the most harrowing scenes of the film take place.

The plot draws on the experiences of Yoo Sang-jun, who escaped North Korea and is now a Christian activist in Seoul. But Mr Yoo was not at the screening, held for foreign press and human rights activists — one of whom has arranged for the film to be shown at the European Parliament in July.

“I don't want to think about my past,” he told The Times. “I hope the film can help the world know about North Korea.”

Mr Yoo's wife and a son died in the North Korean famine of the late 1990s. In 1998 he escaped to China with his surviving son, Chul-min. Despairing of making a living and in fear of deportation — the Chinese authorities routinely send North Korean defectors home, where many face terrible punishment — Mr Yoo put the boy into foster care while he attempted to escape to Seoul.

In 2002 Chul-min set off from China for Mongolia to be reunited with his father. In the barren frontier between the countries, lost, weak and exhausted, he died from exposure. Chul-min is buried under a wooden cross in the Mongolian desert. He was 10.

Filmed in China and Mongolia, Crossing was praised for its realism. “These are stories I hear from North Korean defectors again and again,” Kay Seok, of Human Rights Watch, said.

Kim Tae-kyun, the director of the film, said that he did not use Mr Yoo as a consultant for fear of creating a political incident while filming in China: last year Mr Yoo was imprisoned there for four months for helping North Korean defectors.

But Mr Kim, who felt a “deep sense of shame” as he researched the film, said that half of its proceeds would go to help fugitives from the North and urged South Koreans to take greater interest in the ongoing tragedy.

“It would be pertinent if China's leadership watched this film,” Tim Peters, an American activist and friend of Mr Yoo, said. “With the stroke of a pen, they could stop thousands of tragedies.”

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