(CNN) -- Former Taiwanese President Chen Shui-bian -- who has been on a hunger strike since his arrest last week on corruption charges -- was hospitalized Monday for complications from dehydration, the country's national news agency said.

Doctors treated the 57-year-old former leader with injections of saline and glucose after he began experiencing "an excessively fast heartbeat and tightness in chest," the Central News Agency said.

Chen has refused to eat since he was arrested Wednesday on corruption charges.

The former president, whose term ended in May, is accused of embezzling 600 million Taiwan New Dollars ($18 million). Prosecutors say he also took bribes, laundered money and illegally removed classified documents from the president's office.

Chen has denied any wrongdoing and insists the charges are politically motivated. His party favors independence for Taiwan , while the administration of President Ma Ying-jeou favors closer ties with mainland China .

Nine other people have been arrested in the case, including Chen's former treasurer, and they have agreed to testify against him.