Claire Doole - "Very few other stories have been so instrumental in advancing the cause against enforced disappearances as this film."

With these words, the UN High Commissioner for Human Rights, Louise Arbour, paid tribute to the campaign launched by the families of the Japanese abducted by North Korea in the 1970s and 80s for the return of their loved ones.

Their struggle to find out what happened to their brothers, sisters, sons and daughters who were "spirited away" has been turned into a film by the New Zealand director, Jane Campion. "Abduction: The Megumi Yokota Story" tells of the emotional and relentless quest of the parents of the youngest victim to find their 13-year-old daughter Megumi, who disappeared in November 1977.

For 20 years, Shigeru and Sakie Yokota had no word of their daughter who vanished on her way home from badminton practice in the town of Niigata. It was only in January 1997 that they learned she had been kidnapped by North Korea to train its spies in Japanese language and culture. Gradually, public, media and government indifference turned to anger.

After concerted pressure, North Korea allowed five abductees to return to Japan in 2002, saying the rest had died. But the Yokotas and the other families rejected the claims based on a lack of evidence.

Louise Arbour, who has met the Yokotas twice, praised the family’s "strength, courage and refusal to give up their fight for the truth". The film, she added, had highlighted the importance of the new global treaty outlawing forced disappearances, signed by 57 countries, including Japan, in Paris in February.

Many believe that as many as 250 Japanese have been kidnapped since the 1970s, as well as many South Koreans and people from other countries. Last year, the Association of the Families of Victims Kidnapped by North Korea published evidence that Pyongyang had abducted citizens from at least 12 countries, including Thailand, Lebanon, Romania and China.

Speaking at the film festival in Geneva, its Secretary General, Teraki Masumoto, called the abductions by North Korea "an act of state-sponsored terrorism".

"We urge the international community to act in unison to resolve this issue. We want and need your co-operation," he said.

Since his older sister, Rumiko, left their Tokyo apartment on August 1978, and never returned, Masumoto has tirelessly fought to find her. Like the Yokotas, he disputes Pyongyang’s claims that she is dead.

In the film, he is shown hurling abuse at the former Prime Minister Koizumi, after he returns empty handed from a visit to Pyongyang, despite Tokyo’s promise to restore food aid. However, he has renewed confidence in the abilities of the new Prime Minister, Shinzo Abe, to broker a deal.

"For him, the abductions are a matter of state and national shame. He has said that he is personally ashamed that as a politician he has not been able to resolve the issue."

However despite the Prime Minister’s tough talk, there has been little progress. A bilateral meeting last week in Hanoi on normalising ties was cut short after North Korea reportedly objected to Japan’s stance on the abductions.

Because of the kidnapping row, Japan has so far refused to fund any part of the fuel aid pledged in a recently agreed six party deal aimed at ending North Korea’s nuclear programme.

Some analysts believe that the abduction issue is clouding the real cause for concern for Japan - that of regional security and the denuclearisation of North Korea.

"The kidnappings were terrible, but it is clear where the security threat lies," according to Robert Templer, Asia Programme Director of the International Crisis Group.

However, the Prime Minister has called kidnappings a grave infringement of human rights and they remain an emotive issue in Japan. Faced with public pressure to resolve them, Japan has no option but to keep talking.

"We are still looking to North Korea to give us a full account of the abductions," says the Japanese ambassador to the UN in Geneva, Ichiro Fujisaki. "As long as the families are convinced that their loved ones are alive, we will continue to support them."