TAIPEI - FORMER Taiwanese President Chen Shui-bian was taken from his jail cell to a hospital on Sunday after a five-day hunger strike when a doctor found an irregular heartbeat, a prison official said.

Lee Ta-chu, an official at Tucheng Jail where Chen had been held since last Wednesday for investigation on graft allegations, told The Associated Press a prison doctor recommended Chen's hospitalization after examining him.

Chen 'is having difficulty breathing and is complaining of pain on the left side of his chest,' said Mr Lee, adding that the former president was conscious when taken to the hospital.

Chen arrived at the Far Eastern Memorial Hospital in Panchiao city, 10 minutes after his ambulance left the Tucheng detention centre outside Taipei, TVBS news network said, where he is being held on graft allegations.

'Go! Go! Ah-Bian!' chanted dozens of Chen's supporters outside the hospital, referring to the former leader's nickname, according to the network.

Earlier on Sunday, Chen rejected repeated pleas to end his fast as he spent time reading legal documents about his case in solitary confinement, said Mr Lee.

Chen's blood pressure, pulse and body temperature have dropped and were near the lower margin of safety, Mr Lee said. He declined to say if the former leader would be force-fed if his fast continued.

Chen, an ardent supporter of Taiwan's formal independence from rival China, has denied any wrongdoing and said he is being persecuted by his successor, President Ma Ying-jeou.

Since his arrest, dozens of Chen supporters have protested daily outside the prison, backing his claim of innocence and demanding his release.

The corruption probe began soon after Chen finished eight years in office in May, forcing him to withdraw from his Democratic Progressive Party in disgrace.

But he appeared to have won new support as the pro-independence party used his arrest to step up its criticism of the ruling Nationalists' pro-China policy and their alleged persecution of former officials in Chen's administration.

Prosecutors said they have enough evidence to hold Chen for an unspecified period to prevent him from communicating with alleged co-conspirators as they prepare a formal indictment. They denied any government interference in the case.

In August, Chen admitted he broke the law by not fully disclosing campaign donations he had received, after a Nationalist lawmaker alleged that Chen's son and daughter-in-law moved US$21 million (S$32 million) to Switzerland in 2007.

At the time, prosecutors said they wanted to determine whether the funds were donations left over from political campaigns - as Chen insisted - or whether bribery may have been involved.

His office is planning to stage a mass rally in a Taipei park on November 22 in a show of support.-- AFP, AP