A six-year battle to compensate Hong Kong people forced to cash in their savings and valuables for worthless Japanese banknotes during World War II ended in defeat in a Tokyo court yesterday.

But Ng Yat-hing, the man leading the claim for $11 billion, said they would not give up. "We will continue to press the Japanese Government for a refund, even if it takes 10,000 years."

The father of Mr Ng, who heads the Hong Kong Reparation Association, and 16 other plaintiffs were forced to convert all their money and valuables into Japan's wartime currency in April, 1942, four months after Hong Kong's surrender to Japan.

They lost everything when the currency was declared invalid after the war.

Mr Ng's group claimed the right to compensation under the 1954 Hague Treaty, which defined property rights in war situations.

But Judge Seiichiro Nishioka ruled the treaty did not give individual victims the right to demand compensation against a nation.

Mr Ng branded the court decision "barbaric" and said: "Leaving this shameful act of shirk-off to the next generation will only create more resentment and anger towards the Japanese Government."

The group's lawyer, Kenichi Takagi, said: "Today's verdict symbolises Japan's inconsistency and weakness, which prevent it from winning the trust of other Asian nations."

Of the 17 plaintiffs, five have died.

"It is very sad for them to have died and not to have received fair treatment," said Au Pak-kuen, vice-president of the Hong Kong Professional Teachers' Union, which has helped the plaintiffs pursue their cause since 1993.

"The people were forced to buy the wartime note at a rate of HK$4 for one," he said, adding: "People also received their salary in wartime currency."

He estimated 3,500 families still hold the currency.