"Japan - reveal the truth! Admit the crime! Officially apologise! Punish the criminals!" South Korean protesters chant every Wednesday outside the Japanese Embassy in Seoul.

They are the survivors of the brutal, Asia-wide system of sex slaves for the Imperial Japanese Army, which the military government encouraged and helped to operate for 13 years, from 1932 until the end of World War II in 1945.

Japan says all potential claims by individuals for sufferings inflicted in the war were closed years ago, by treaties normalising its ties with other Asian countries.

But Kang Kyung-wha, a senior official at South Korea's foreign ministry, has recently urged Japan to come to terms with its "legal responsibility" and human rights obligations towards the former comfort women.

Her story is typical of the tens of thousands - some estimates say 200,000 - women from across Asia whose lives were ruined when they became military sex slaves to the Japanese.

At the age of 17, she was tricked into being abducted by a Korean middle-man who delivered large numbers of young women and girls to his country's then Japanese colonial masters.

She was taken by train to the so-called comfort stations for the Japanese army in Manchuria, north-east China, where she says she was raped by the soldiers many times a day for three years.

According to Mr Chang, Japan's first admission of involvement only came in 1991, after a wartime document came to light in the foreign ministry about the granting of travel permits for Asian women in areas occupied by the Japanese army.

He says that, since then, the Japanese authorities have continued to hinder the search for detailed evidence about the fate of the former comfort women.

But his own research team's trawl through America's national archives has produced a sheaf of files captured by the US army from the retreating Japanese forces.

They contain photos and other personal details of dozens of young Filipino women - evidence, he says, of the most extensive system of female trafficking the world has ever seen.

In 1995 the Japanese government took its boldest step so far, setting up an Asian Women's Fund, which collected private donations and sent "atonement money" worth $30,000 or more to each of 364 former comfort women in Taiwan, the Philippines and South Korea.

Many of the Korean victims, he says, were put under intense social pressures to refuse the Japanese donations, although they sorely needed that support.

Kim Gunja now lives near Seoul in a home for former comfort women supported by the South Korean government. She says she hopes Japan will reveal the truth and offer her official compensation.

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