Taiwan's high court has rejected former Taiwan leader Chenshui-bian's appeal against his conviction for graft.

But the court reduced Chen's sentence of life imprisonment to 20 years in jail. His wife Wu Shu-chen's life sentence was also reduced to 20 years by the high court.

The court is also considering whether to uphold the decision of continuing to detain Chen, who has been in custody for more than 500 days.

Chen and his wife were both sentenced to life imprisonment by the Taipei District Court in September last year for corruption, embezzlement, money laundering and other abuses when he was in power from 2000 to 2008.

They were found to have embezzled 104 million New Taiwan dollars, or around 3.15 million US dollars, of public funds.