Prosecutors said yesterday they would summon ex-Taiwan leader Chen Shui-bian and four of his family members for interrogation in regards to an overseas money-laundering case.

The others are Chen's wife Wu Shu-chen, son Chen Chih-chung, daughter-in-law Huang Jui-ching and brother-in-law Wu Ching-mao.

Prosecutors will also question Yeh Sheng-mao, former head of Taiwan's "investigation bureau," for allegedly concealing information on Chen's case, and George Liu, Taiwan's former "representative" to Switzerland, for allegedly delaying a notice of assistance for an investigation by the Swiss side.

Prosecutors found Chen's family had remitted large sums of money worth nearly 1 billion N.T. dollars (31.9 million U.S. dollars) to bank accounts in Switzerland, Singapore, Cayman Islands and other countries.

Currently, Chen has been barred from leaving the island, while his son and daughter-in-law left for the United States a few days before the money-laundering issue was exposed by Taiwan media last week.

In related developments, Wu Shu-chen's sister-in-law was suspected of a suicide attempt by taking excessive sleeping pills after she was summonsed by prosecutors for the probe. But Wu Ching-mao denied it and said his wife had taken too many of the pills due to pressure.