But after Madam Lee, 43, was found dead in a canal near Sims Avenue in 2000, a shocked Mr Leck learnt that his wife of 19 years had been leading another life in secret, one that had made her a millionaire.

A coroner's inquiry recorded an open verdict and police did not suspect foul play but Mr Leck, a car sales manager, is not satisfied.

After her funeral, he stumbled across his wife's chest of secrets inside a locked bedroom drawer. It held cheques, IOUs, promissory notes and investment contracts amounting to $1.9 million. One cheque was made out for $519,000. There were also returned cheques, police reports and some photocopies of identity cards.

The documents suggest Madam Lee was a moneylender or involved in dodgy business deals, said Mr Leck, 52. 'I was beyond shocked,' he recalled. 'How did she make so much money?'

Mr Leck also found a $10,000 diamond necklace - the same one he had stopped her from buying because it was too extravagant.

'I told her that she doesn't go to functions and she doesn't need to wear a diamond necklace to the market,' he said. 'But she was always so secretive.'

Though Mr Leck handed over the documents for police investigations, the case has grown cold.

In 2006, he asked Crime Library Singapore for help, offering $10,000 for information about his wife's case. Last week, he raised the reward to $15,000.

In her 20s Madam Lee was a secretary in an engineering firm but quit after son Ritchie was born and was then mostly a housewife for 16 years.

Just before she died, she worked at a bookshop in Canberra Secondary School for $750 a month.

Madam Lily Sui, 63, owner of the bookshop at Ritchie's school, Yishun Town Secondary, befriended Madam Lee when she showed up to ensure Ritchie did not play truant.

Madam Lee then volunteered to help Madam Sui at the Canberra shop. Madam Sui would look out for Ritchie in return.

But Madam Lee was also leading her parallel life, which included making a killing on the stock market. 'She started playing in 1987 after the market crashed and I think she made quite a bit of money,' said Mr Leck.

But she never said how much and the couple kept separate bank accounts.

She was constantly looking for money-making opportunities. Friends and family members told The Sunday Times she had offered to pump cash into their various ventures, including $400,000 into brother Steven's transport firm.

Madam Lee also pestered her husband to start his own car business and told him not to 'worry about the money'. And several times she hinted that she was interested in a money-changing business and flared up when Mr Leck objected.

Mr Leck also found several newspaper cuttings of companies looking for investors in the drawer. Madam Lee appeared to have responded to them.

Mr Terry Foo, who said he once owed Madam Lee $56,000, told The Sunday Times she had replied to an advertisement he and his partner took out. After a visit, she declined to invest but offered to lend them the money at 15 per cent interest.

After signing some IOUs, she wrote a cheque. Mr Foo then mailed her a repayment cheque every month.

'Though she operated like a loan shark, she never harassed me when I had to delay payments,' said Mr Foo. 'She would only remind and give me one to two days' extension.'

He claims he still owes her about $20,000, but stopped payments after reading about her death.

Madam Sui also recalled Madam Lee saying she had 'business dealings' with a man named Michael and had lent him some money.

The night she disappeared, Madam Sui had spoken to her at around 7pm. 'She was in a hurry and said she was meeting Michael at Khatib.'

Mr Leck made a missing-person report when his wife did not return home or answer her mobile phone. He then flew to Bangkok for a 'temple appointment'.

'I had already booked the tickets,' he said, but cut short the trip when his brother-in-law told him a body had been found in a canal.

The mystery of the man called Michael has continued to haunt Mr Leck. It appeared from documents that this Michael owed Madam Lee over $100,000.

When Mr Leck tried to deposit the post-dated cheques into his wife's account, they all bounced.

He described his wife, who did her O levels at St Joseph's Convent, as 'plain' and said she 'did not show off'. Though she had two Rolex watches and some diamond necklaces, she hardly wore them.

'You looked at her, no way you'd know she was so rich,' he added.

But her brothers and friends paint a different picture. She was dressed in 'fashionable clothes' and 'expensive jewellery' with designer bags.

Though Mr Leck could not claim any money from the bounced cheques, Madam Lee still left him $1.2 million in shares, $50,000 in her bank and more than $100,000 in insurance payouts.

Now he wants the police to re-open the case and hopes the $15,000 reward will shed new light on the case.

'I still believe someone plotted her death,' he said. 'I want justice for my wife.'

He has ruled out accidental drowning, saying his wife was a strong swimmer. Besides, her jewels, wallet and keys were also missing.

And suicide was even more preposterous. Mr Leck said his wife would never have killed herself in the midst of their son's O levels.

Also, if she chose suicide, throwing herself into a canal would not be her way.

'She liked to be clean and pretty; she wouldn't commit suicide this way,' he said.

mavistoh@sph.com.sg