A DEEPENING mystery about the whereabouts of disgraced Japanese star trader Mr Yasuo Hamanaka fuelled anxieties in a fragile world copper market yesterday.

Ten days on from his eclipse, Mr Hamanaka mesmerised fellow dealers with a vanishing act just as he had kept them guessing throughout the decade when he called the tune in the murky London based trade in copper.

Rumours around the London Metal Exchange (LME) have variously had him fleeing Japan, mysteriously popping up in London and sending someone to fetch the family dog to a secret Japanese retreat from his otherwise empty Tokyo home.

Yesterday brought a report in the London Times that Mr Hamanaka (48) was being held by Japanese authorities in a "safe house". It said he was "spirited" there for extensive debriefing before news broke on June 13th that he had confessed to losses of $1.8 billion (£1.14 billion) in the rogue dealings for which Sumitomo Corp of Japan said it had sacked him.

Japanese officials said that they were unaware of this. They added that Mr Hamanaka had not been arrested or formally charged with any crime in Japan.

Adding to the mystery, officials at the British Serious Fraud Office, which plans to send investigators to Tokyo this week, are unwilling to say categorically whether they hope to see Mr Hamanaka himself.

Nerves are jangled in the copper market because, so far, few dealers seem to know just how much copper Mr Hamanaka had held that, at some time, must be disposed of by Sumitomo.

Copper prices this week sank to a 21/2 year low. They are one third lower than early May when rumours that Mr Hamanaka was in trouble began to circulate.