Former Taiwan leader Chen Shui-bian was sent back to jail yesterday because of the severity of the graft charges against him, a court spokesman said.

Chen became the first former leader of the island to be indicted after prosecutors charged him and more than 10 other family members and aides on December 12 with corruption, forgery and money laundering.

Chen was arrested last month and held in jail until his conditional release on December 13. The Taipei District Court ordered Chen back to jail at 2:20 am local time after more than 12 hours of deliberation, because of the gravity of his alleged crime and for fear that he could alter evidence, court officials told reporters.

Chen was taken back to the Tucheng detention center in suburban Taipei at 3:50 am but the court verdict allowed him to meet his lawyer and family.

At the beginning of the Monday hearing, Chen's lawyer requested the withdrawal of the judge to prevent the trial from being carried out. But the request was overruled. The court's move reversed its previous ruling that Chen could remain free while preparations for his trial went forward. It followed a judicial decision last week to change the judges presiding over Chen's case.

In a statement yesterday, the Taipei District Court said Chen's detention was necessary for his trial to be carried out smoothly.

"Out of concerns for human rights and the public interest, Chen Shui-bian should be detained but he should also be allowed to receive visitors," the statement said.

The district court had earlier agreed twice to release Chen without bail. Prosecutors challenged the verdicts twice in a higher court. Chen denies wrongdoing and has described the probe involving him as a political plot. Chen's lawyers say they will appeal the new detention order.

Prosecutors said they would recommend the heaviest possible sentence for the charges. They accuse Chen and his wife together of embezzling NT$104 million ($3 million) from a special "presidential" fund when he was "president" from 2000-2008.

They also accuse him of accepting bribes totaling about $9 million related to a land procurement deal and another $2.73 million in kickbacks to help a contractor win a tender for a government construction project.

Chen's trial is due to begin in March, local media said.