Bobby Fischer has been on the run for years

His supporters said he got into a scuffle with prison guards last week after being denied an extra egg.

The American - wanted in the US for breaking sanctions - has been detained since trying to leave Japan last July.

But Iceland has offered him refuge - a former MP said he had been granted an Icelandic passport.

"His passport is waiting for him at the embassy," said former parliamentarian Gudmundur Thorarinsson, after meeting Mr Fischer on Monday, the day after he was released from solitary confinement.

In the struggle, Mr Fischer's fist punched the face of one of the officials Miyoko Watai Bobby Fischer's fiancee Iceland fond of Fischer

But he said Japanese authorities were refusing to release the chess great from detention, and "we don't understand why".

Iceland remembers Mr Fischer fondly since he played a world championship match there in 1972, beating the Soviet Union's Boris Spassky.

Mr Fischer's fiancee also visited him in jail, and said he was showing signs of extreme fatigue.

"He is at the end of his rope, physically and mentally," said Miyoko Watai, a former Japanese women's chess champion.

She explained that Mr Fischer had requested a hard-boiled egg, which was refused.

When he grabbed a guard in protest, she said, other guards rushed in to restrain him.

"In the struggle, Mr Fischer's fist punched the face of one of the officials," she said.

Tax charges

The former American hero is wanted by his home country for violating international sanctions by playing chess in Yugoslavia during its war in 1992.

A Japanese newspaper reported on Sunday that the US was also preparing tax evasion charges against him, which would oblige Japan to hand him over.

"It is completely beyond our understanding why he is treated like a serious criminal," said political activist Gardar Sverrisson.

Mr Fischer's supporters say the US deportation order is politically motivated.

The American exile angered many of his fellow countrymen when he went on Philippine radio on 11 September 2001, applauding the attacks on the US on that day and launching into an anti-Semitic diatribe.