Taipei - Taiwan's embattled former president Chen Shui-bian began a hunger strike to protest what he claimed was unfair prosecution of alleged corruption, officials said Saturday.

"He has not taken any food since Friday, but he has drunk water," said Lee Ta-chu, deputy director of Taipei Detention Centre, where Chen was under custody for the second time since late December.

Chen was first detained in November on suspicion of embezzlement, taking bribes, money laundering and document forgery, but was released on bond after being indicted in mid-December.

But prosecutors succeeded in convincing the court to detain him again in late December, citing the possibility that Chen might flee abroad and threaten witnesses testifying against him.

In a pretrial court hearing in January, Chen pleaded not guilty to all charges.

Lee said prison officials asked Chen to take care of himself and resume eating. "But he wouldn't listen. He has been reading documents brought to him by his lawyers in the past two days," Lee said.

Lee said he sent doctors to Chen's cell to check his blood sugar and health condition Saturday morning.

Chen's friend Cheng Cheng-yu, head of the pro-independence South Society, said the ex-president decided to go on hunger strike again to protest the government of China-friendly president Ma Ying-jeou.

"The former president thought that it was highly unfair for the Ma government to detain him and to voice his indignation against the mistreatment, he decided to stage the hunger strike," Cheng said.

Chen insists the indictment and legal proceedings against him are political persecution by Ma to appease China, which wants to punish Chen for promoting Taiwan independence.

China regards Taiwan as a wayward province that must be brought back to the Chinese fold, if necessary by force. The two sides split at the end of a civil war in 1949.

Chen is scheduled to appear in court for another round of three-day pretrial hearings beginning Tuesday. (dpa)