SINGAPORE, Jan 19 — The charging of former Transport Minister S Iswaran with 27 offences mostly related to bribery and corruption is not the first time that such allegations have been levelled at high-ranking government officials here.

In a reflection of the country’s longstanding zero-tolerance stance towards corruption, at least two other former ministers in Singapore’s history have been investigated and dealt with according to the law.

In a speech he made in Parliament in August last year, Prime Minister Lee Hsien Loong noted that all these past cases were handled by the late founding prime minister Lee Kuan Yew "thoroughly, transparently, and applying the full force of the law”.

On Wednesday, Mr Lee accepted Iswaran’s resignation as a Cabinet minister, Member of Parliament (MP) and from the ruling People’s Action Party.

TODAY takes a look at some other corruption cases involving former ministers.

Tan Kia Gan, former Minister for National Development, 1966

In August 1966, Tan Kia Gan, a former Minister for National Development, was investigated for trying to help his close businessman friend Lim Tjin Hauw and his son William Lim clinch the sale of a Boeing aircraft for Malaysian Airways.

Tan, who was part of founding prime minister Lee Kuan Yew’s first Cabinet, also acted as an intermediary for his brother-in-law in the sale of a tin mine to the older Lim.

In return, he was given 70,000 shares worth S$1 each.

Tan was charged and convicted over the Boeing deal, the current Law and Home Affairs Minister K Shanmugam said in a 2009 speech.

Archived records from the Corrupt Practices Investigation Bureau (CPIB) state: "As the witnesses did not want to implicate him then, Tan was administratively stripped of all his public appointments by the Government.”

At the time of charging, Tan was no longer a minister, since he had lost his seat in the 1963 General Election.

Wee Toon Boon, former Minister of State for the Environment, 1975

In April 1975, Wee Toon Boon, then Minister of State for the Environment, was charged with corruption involving S$839,023.

Investigations revealed that he was linked with millionaire and property developer Lauw Tjin Ho, who was the chairman of property firm Lauw and Sons.

Wee had used his power as a minister to make representations to civil servants on behalf of Lauw.

In return, he was rewarded with a bungalow worth S$532,000, galvanised roofing for his home worth S$3,500, free air tickets for him and his family to Indonesia and bank overdrafts totalling S$300,000 to speculate in shares.

Wee was convicted of corruption and sentenced to 4.5 years in jail and had to pay a penalty of around S$7,000.

His jail sentence was later reduced to 18 months after he successfully appealed against one of the five charges.

Teh Cheang Wan, former Minister for National Development, 1986

In November 1986, CPIB investigated Teh Cheang Wan, then Minister for National Development, for allegedly accepting bribes.

Teh was accused of accepting two bribes of S$400,000 each in 1981 and 1982. He had held his ministerial role since 1979.

He was accused of accepting the bribes from two private companies — Hock Tat Development and Keck Seng — which he had allegedly helped to retain and buy a piece of state land for private development.

On Dec 14 in 1986, Teh committed suicide at his home by overdosing on barbiturates, a sedative medication, before he could be formally charged for his offences.

He maintained that he was innocent up till his death. — TODAY