Singapore has a strong anti-corruption system and values but it is not the system that will continue keeping it clean. It is the people who run it who will do so, said Prime Minister Lee Hsien Loong.

He made this point on Friday during a dialogue at independent think-tank Chatham House, while responding to questions from Mr Malcolm Rifkind, the chair, and an audience of academics, diplomats and London's intellectual elite.

Mr Rifkind, a former minister in the Conservative Government of prime ministers Margaret Thatcher and John Major, asked what Mr Lee felt was Singapore's unique selling point.

He replied that it was a first world system in a very complicated and non-first world part of the world. Things work, people are well-educated and the government is incorruptible, efficient, and tries to be consistent over a long period.

"So if you come to Singapore, and you want to do business, you can count on what we promise you, and what you see is what you get and that's not bad," Mr Lee said.

Mr Rifkind noted that the abhorrence of corruption went back to the days of former prime minister Lee Kuan Yew. Were there strains in the system now?

Mr Lee said that the system and people's values were fairly well-entrenched. The public's expectations were also such that if something was not quite right, the alarm would be sounded, investigations begun if indeed there was real suspicion, and consequences followed.

"It doesn't mean that the system runs by itself. In the end it is still people and you must have very capable, honest and very resolute people who will operate the system and follow through and keep it clean even when it's politically inconvenient.

"And that's what we tell Singaporeans: You cannot assume that whoever happens to be the minister or prime minister, all will be well because we've got all these rule books and laws built up. It depends on what sort of person he is and who is going to make it work."

On what made it possible for Singapore to be corruption-free when so many others had failed, Mr Lee said that the British did leave behind a system, but the PAP also felt it important to win the first elections in 1959 "because by the second time, the system may well have gone corrupt".

He said that Singapore had an exceptional team with the resolve to keep things clean and build a system to maintain it, and with a track record of investigating anyone at fault, whether a policeman or a minister.

But he acknowledged that it was easier for a small country with just one level of government to weed out corruption. Other countries, he said, can decide to go about it gradually or through revolution.