Prosecutors have stopped Mr Chen and his brother-in-law Wu Ching-mao from going abroad, after searching Mr Chen's home and office and Mr Wu's home earlier in the day, The China Post reported yesterday.

Investigators say they have found details of four secret bank accounts opened in 2000, the year Mr Chen won the presidential election.

The four accounts hold a total of $T500 million ($18.4 million), which Mr Chen's wife, Wu Shu-chen, insisted were family savings.

The Supreme Prosecutor's Office launched the investigation after Mr Chen admitted at a news conference Thursday that his wife had remitted $US20 million ($23 million) into a Swiss bank account last January without telling him. He said this was done in preparation for their possible retirement abroad.

Mr Chen said the money was from campaign funds that he had failed to declare. But prosecutors are trying to determine if the couple were attempting to launder illegally obtained money.

Local media reported that Mrs Chen used the bank accounts of her elder brother Wu Ching-mao, her son Chen Chih-chung and daughter-in-law Huang Jui-ching to transfer money to a Swiss bank account.

Deutsche Presse Agentur