When Evan Yeo Oon Beng retired as the longest-serving director of the Corrupt Practices Investigation Bureau (CPIB) in 1994, former prime minister Lee Kuan Yew wrote to him, saying "You have done well for your country".
That endorsement capped a long career for Mr Yeo, who died on Tuesday last week from pneumonia after a stroke left him in a coma for about five weeks. He was 79.
In the course of 40 years in the public service which included 14 years as director of the CPIB, Mr Yeo received numerous other awards and accolades, including the Public Administration Medal (Gold) in the 1994 National Day Awards.
But it is understood that Mr Lee's note took pride of place for Mr Yeo.
Known to be "upright, forthright and outright", the low-profile and publicity-shy crime buster presided over several high-profile cases that were to cement Singapore's zero-tolerance reputation for graft.
These included the 31-month probe on then National Development Minister Teh Cheang Wan in 1986 for allegedly accepting $1 million in bribes. Mr Teh committed suicide in December that year. A subsequent inquiry commission said Mr Teh might never have been found out if not for the CPIB's commitment to fearless investigation and its perseverance in checking every lead.
Another probe led to the 1981 conviction of English engineer William Wilkinson, who took $80,000 in bribes to help award contracts for a $400 million complex which produces petrochemical products.
Mr Yeo, who started as a police officer in 1954 and trained in London's Scotland Yard, took pride in his job. In a speech to civil servants during his term, he said: "Singapore has a fine reputation of having a clean administration. People know they do not have to give bribes in order to get things done."
He held various appointments and headed the Police Academy before being posted to the CPIB in 1978 as deputy director and became director in 1980.
The bureau paid tribute to Mr Yeo yesterday, saying: "He progressively built up CPIB, laying strong foundations for the bureau to be the effective anti-corruption organisation that it is today. More importantly, he imparted a strong sense of purpose and mission in its officers, many who still fondly remember his leadership and stewardship to this day."
Mr Yeo leaves behind his wife, a son and daughter, and seven grandchildren.
His family declined to be interviewed but said in a statement to The Straits Times: "Our father was a God-fearing and hard-working man, and he highly respected the Government and people of Singapore whom he served for 40 years.
"He was a man of character and principle, and always strived to keep a low profile and not dwell too much on his achievements, which he saw as being part and parcel of his duty. We are very proud of his contributions to the country, and his devotion to us and we shall miss him dearly."