Chen junior and his wife left for the U.S. Aug. 9, together with their baby daughter and Wu, several days before the unmasking of an alleged money laundering scandal involving the couple and the ex-president.

Wu and her baby granddaughter Chen Chieh-hsin took the EVA Airways' BR031 Taipei-bound flight from New York, scheduled to arrive at Taoyuan International Airport at 5:30 a.m.

Wu told reporters she didn't know anything about the money laundering allegations, adding that Chen and Huang would return to Taipei after registering at the University of Virginia.

Originally, Chen junior and Huang were scheduled to take a trip back to Taiwan on Jan. 19, 2009.

However, it seems Chen junior and his wife were forced to advance their return to Taiwan to face investigation over their alleged roles in the money laundering case involving the former first family.

Just two days earlier, prosecutors questioned the ex-president and his wife Wu Shu-jen about the suspected US$20 million in Huang Jui-ching's bank accounts in Switzerland with Chen junior holding power of attorney.

The prosecutors asked the ex-president and his wife to tell their son and daughter-in-law to return to Taipei and face the investigations into their alleged roles in the money laundering case as soon as possible.

The young couple could be fingered as accomplices if their parents were found to have been involved in the alleged money laundering scandal, police said.

They will also face daunting legal troubles if the sources of the funds deposited in their bank accounts by their parents originated from illegal sources.

Officials at the Ministry of Finance plan to to impose a gift tax if the funds were given to the young couple as a gift.

Meanwhile, prosecutors have have barred ex-president Chen and his wife from leaving the country pending further investigation into their suspected roles in the "state affairs fund" embezzlement case and the money laundering case.

They have been listed as defendants in both cases.