He was a known miser, and Mr Loh Kum Mow was so tight-fisted that he only fixed the roof of his house when it was about to collapse, and repainted it when the authorities issued him a warning.

But the late Mr Loh turned out to be a generous soul, as his family discovered after his death in December 2016 — at the age of 89 — that the former sub-accountant had left a portion of his S$20 million wealth to charity.

Mr Loh, who died of old age, donated a total of S$3.35 million to four charities – National Kidney Foundation (NKF), Thye Hua Kwan Moral Charities, Ren Ci Hospital and Bo Tien Welfare Services Society – which received close to S$840,000 each. The organisations were informed of the bequest two to three months ago when Mr Loh's shares were fully liquidated.

The rest of his fortune was portioned out to his four nephews and nieces, who inherited 13.75 per cent each, and his three sisters received six per cent each.

Giving a glimpse into the person Mr Loh was, Mr Charlie Loh, his nephew and executor of his will, said his uncle was a "self-made man" who came from a poor family of fishmongers. Little is known about his childhood and life, only that he lived apart from his family from a young age, and did translation work for the Japanese during the occupation in World War II.

Although he only had a few years of formal education in Mandarin, he earned an accountancy Cambridge certification when he was in his 30s, said Mr Charlie Loh. The 65-year-old pieced together information about his uncle after he inherited his Bukit Timah house and went through his belongings.

Mr Loh's job as a sub-accountant at Public Insurance Company (now called MS First Capital Insurance), plus his investments in the stock market, allowed him to amass a fortune that surprised his relatives.

However, his spending habits were unlike that of a wealthy man. Mr Charlie Loh said he dressed simply and did not own any branded goods except for a Seiko watch, which was repaired many times. His wife, who was a typist and a colleague at the firm, was also frugal. The couple married when Mr Loh was in his 40s, and they had no children.

But Mr Loh was a responsible family man, said his nephew, as he had paid his grandmother's nursing home fees for five years after she was bedridden, hit by dementia and needed a feeding tube.

The Guangdong-born Mr Loh, who immigrated to Singapore when he was three, also never failed to send annual sums of money back home to his extended family in China. His final wish in 2014 before his death two years later was to make a trip to Shantou to visit relatives, said Mr Charlie Loh, who helped organise it.

Mr Charlie Loh said his uncle had selected the charities for his donations in 2012 shortly after his wife's death, and he had asked him to arrange for a lawyer to help draft his will.

NKF could have been picked as a beneficiary as Mr Loh was a diabetic patient for over 40 years, said the younger Loh. The others could have been selected because he had witnessed the suffering of patients with chronic diseases, including his own mother and wife.