Taiwan prosecutors on Saturday questioned the island's former leader Chen Shui-bian's wife in connection with money-laundering claims.
Chen's wife Wu Shu-chen was asked to explain overseas money transactions by prosecutors, and Chen's home was searched on Saturday morning in connection with investigations into the embezzlement of "confidential funds" of the Taiwan authority.
Prosecutors have kicked off a sweeping investigation on the Chen family's funds in Taiwan and outside the island.
Chen admitted Thursday that he failed to fully declare his campaign funds, saying his wife transferred these funds abroad without informing him. Chen did not disclose the amount of remittances and denied any corruption during his tenure.
Chen and his wife then quit the Democratic Progressive Party (DPP) on Friday.
A Kuomintang (KMT) party member on Saturday also alleged that Chen's wife bought jewelry to launder money.
Some of his opponents, including Hung Hsiu-chu from the KMT, charged that Chen's family had opened four bank accounts in Switzerland, with total deposits of almost 1 billion New Taiwan dollars (about 32 million U.S. dollars).
Hung said that Chen had remitted large sums abroad through his daughter-in-law, Huang Jui-ching.
However, Chen's son and daughter-in-law, two key witnesses in the case, left Taiwan for the United States last Saturday. Prosecutors suspected they were evading the investigation.
Chen said he did not know when his son and daughter-in-law would return to Taiwan, when he was summoned for a second time on Friday afternoon.
Taiwan's judicial department confirmed on Thursday that the Swiss judicial authorities had sought Taiwan's assistance in probing the source of money belonging to Chen's son and daughter-in-law, as they suspected it could be a money-laundering case.
The DPP has received protest calls from supporters since the scandal was uncovered. Some DPP supporters said they had donated a lot of money to support Chen's elections, and now feared that it had been embezzled.
Some DPP members said they felt angry and ashamed, asking for a thorough, timely investigation, "otherwise we would resign from the party together."