The three-judge High Court panel came to its decision early yesterday morning, six hours after beginning a hearing attended by Chen and his three attorneys.

The session was a result of a decision by the Supreme Court Thursday afternoon to accept a protest by Chen against the Sept. 24 High Court decision to extend his detention by three months.

The former president has been in prison since Dec. 30, and was sentenced by the Taipei District Court to life in jail and a NT$200 million fine in several cases of corruption and money laundering on Sept. 11.

At the latest hearing, the High Court still ruled there was a need to keep Chen detained, rejecting his attorneys' arguments one by one.

Court spokesman Wen Yao-yuan said that because of the seriousness of his crimes and of his far-reaching influence, Chen should stay in custody.

The judges accepted the argument from the prosecutors that the former president posed a flight risk.

"He is naturally more familiar than ordinary people with ways to flee overseas," Wen told reporters, reading a statement from the court.

Chen's long experience as a president from 2000 to 2008 had given him numerous overseas contacts, while his relatives still had assets overseas, the court reasoned.

The presence of government-supplied bodyguards did not mean Chen would be unable to flee the country, Wen said, because their task was to protect him against outside threats, not to restrict his movements.

The court cases against him would be difficult to handle if Chen was let out of prison, the High Court argued.

During Thursday's session, Chen and his attorneys had proposed he would stay under house arrest and surrender his passport.

However, Chen also created a new controversy by revealing the existence of allegedly secret passages allowing any president to escape.

In order to defend his case he would not run off, Chen said he knew of a secret passage a president could use to escape from the Presidential Office to the Ministry of National Defense and to board a helicopter on the latter's roof. There was a similar passage near a military command center in the hills north of Taipei, he reportedly said.

Ruling Kuomintang lawmakers accused Chen of leaking state secrets and of destroying the usefulness of the secret escape routes by revealing their location.

After the High Court hearing finished early yesterday morning, Chen was returned to the Taipei Detention Center in Tucheng, Taipei County, without being allowed to speak to reporters. He left groups of disappointed supporters behind who had hoped the Supreme Court ruling provided the best chance for the former president to be freed.

Chen has proclaimed his innocence and repeatedly accused the judiciary of working with the administration of President Ma Ying-jeou in a politically motivated plot of revenge against him.

Chen's next move will be to prepare for his appeals process before the same High Court which decided twice to keep him in custody.

The appeals procedure started yesterday, with three former presidential aides appearing in the case surrounding the alleged misuse of special state affairs funds. Chen himself was scheduled to attend at a preparatory session on Oct. 23, reports said yesterday.