OVER a period of eight years, a wealthy Indonesian-Chinese woman's son-in-law chalked up a debt of US$17.5 million (S$26.5 million) with American Express Bank.

He racked up the debt from loans and losses incurred from foreign exchange trades.

In March last year, the bank deducted this sum of money from Madam Susilawati's account to offset Mr Tommy Lim Thian Long's debt.

The bank's position is that it was entitled to do so because in 1998, she signed a document pledging the money in her account for use to cover Mr Lim's liabilities to the bank.

In a case that opened in the High Court yesterday, the 58-year-old woman is suing the bank to recover her money.

Her lawyers from Tan Kok Quan Partnership contended that the document in question cannot be used to support the bank's claim because Madam Susilawati signed the document under the 'undue influence' of her son-in-law, and that the bank knew of this. They also argued the bank had breached its fiduciary duties to her.

In her affidavit, Madam Susilawati said she studied in Chinese schools and was not literate in English.

After marrying Indonesian businessman Gustimego in 1966, she stayed at home, and raised their five children.

She first opened a Citibank account in Singapore in mid-1997 on her son-in-law's advice. Later that year, she opened an account with Amex, also on his suggestion.

He managed her accounts and she trusted him because 'Tommy was my son-in-law'.

She said it was only in November 2005 that she learnt about the document pledging her money to cover his debts.

Madam Susilawati told the court yesterday that she signed the document 'willingly' but did not understand the terms. She added that Mr Lim had told her about it in 'one or two words' and that no bank employee explained it to her.

However, the bank's lawyers from Rajah & Tann asserted that she was fully aware of what she had signed, as her relationship manager had explained it to her.

They described her as an experienced investor and a high net-worth individual making her own financial decisions.

It emerged in court yesterday that apart from the Amex account, she had also agreed to stand surety for Mr Lim using her Citibank account.

She told the court that, in late 2002, she had tried to transfer US$6 million from that account but was told she could use only US$1 million - the rest was 'tied up' for Mr Lim.

She has sent a lawyer's letter to Citibank but has yet to launch court proceedings.

The trial continues.