HE WARNED Australians they risked becoming the "white trash of Asia" and crushed his political opponents at home. He made laws banning chewing gum and jukeboxes and imposed severe restrictions on freedom of speech.

But Lee Kuan Yew, who has died aged 91, turned an island at the tip of the Malaysian peninsula into a glittering regional financial and technology powerhouse with a $US300 billion a year economy.

Mr Lee was a towering figure on the international stage, a man of integrity who stood apart from other Asian nation-builders because he did not become corrupt.

The Cambridge-educated lawyer - who ditched his Anglicised name Harry Lee for his original Chinese name - had a relentless urge to smash those who crossed him, overseeing a system where his opponents were jailed or driven into bankruptcy through costly libel suits; the media was stifled - often through libel suits; and political dissent was crushed.

Chia Thye Poh, a physics lecturer and member of Singapore's parliament in 1966, refused to bow to Mr Lee, a decision that led him to become one of the world's longest serving political prisoners.

Mr Lee had accused Mr Chia of being a member of the Communist Party of Malaya and ordered him to sign a declaration renouncing violence. Mr Chia refused.

Twenty-five years later Mr Chia was still incarcerated, by then confined to a small, brick guardhouse on Singapore's Sentosa island where he described Mr Lee's refusal to release him as mental torture.

"To renounce violence is to imply you advocated violence before. If I had signed the statement I would not have lived in peace," he said at the time.

The restrictions on Mr Chia, who was never convicted of any crime, were not lifted until 1998.

But Mr Lee's strong grip and dominant personality shaped Singapore into becoming a place envied by most of the world where everything seems to work with super-efficiency.

"You take me on. I take my hatchet, we meet in the cul-de-sac," Mr Lee once said when referring to the late Workers Party leader J.B. Jeyaretnam.

"That's the way I had to survive in the past. That's the way the communists tackled me."

Mr Lee never trumpeted the virtues of democracy and made his contempt for "one man one vote" clear, despite his People's Action Party being returned to power in every election since 1959 and currently holding 80 of 87 seats in parliament.

"If I were in authority in Singapore indefinitely, without having to ask those who are governing whether they like what is being done, then I have not the slightest doubt that I could govern much more effectively in their own interests," he said in 1962.

Mr Lee questioned the way regional nations pursued democracy.

"With few exceptions, democracy has not brought good governance to the new developing countries - Westerners value the freedoms and liberties of the individual," he said in 1990.

"As an Asian of Chinese cultural background, my values are for a government which is honest, effective and efficient."

If Mr Lee had lived a few months longer he would have witnessed the celebration of Singapore's 50th anniversary on August 9.

His physician daughter Lee Wei Ling revealed that he had been battling a neurological disease that made it difficult for him to walk.

In one of his last public appearances, Mr Lee received a standing ovation at a ceremony marking the 60th anniversary of the founding of the People's Action Party.

Mr Lee led Singapore as prime minister from 1959 to 1990 and went on to play an influential role as senior minister from 1990 to 2004 under his successor Goh Chok Tong, and then minister mentor from 2004 to 2011 under the country's third prime minister - his son, Lee Hsien Loong.

The elder Mr Lee's greatest priority was his nation's economy, which gave Singaporeans a higher standard of living than Britain, the United States and Norway.

In 1960, Singapore's GDP per capita was $US427 per person; in 2013 it was more than $US55,000 per person.

With Mr Lee's relentless energy Singapore built the region's finest airport, roads, communications network and health system. He established a private housing system and pension scheme that gave every citizen a stake in the system.

"We had to make extraordinary efforts to become a tightly knit, rugged and adaptable people who could do things better and cheaper than our neighbors, because they wanted to bypass us," he wrote in his autobiography.

Mr Lee's passing will be a difficult time for Singaporeans amid an outpouring of grief and accolades for the man who oversaw the island's independence from both Britain and Malaysia.

"Just like all the great men who built south-east Asia in the post-colonial period, Lee Kuan Yew is a presence as long as he breathes," said Ernest Bower, an expert on the region at the Centre for Strategic and International Studies.

"Singapore is now looking for change and evolution but they're not sure. I think there's a little bit of fear and anxiety about all this," he said.

Prime Minister Lee Hsien Loong has acknowledged Singapore is at an "inflection point" and faces some of the same challenges of developing countries, citing an ageing society, generational changes and the need for economic transformation.

"We are strengthening safety nets so that we can prepare for the uncertainties ahead," he said.

Opposition parties are expected to win more seats at elections to be held next year.

Carlton Tan, a 28 year-old Singaporean commentator, believes younger Singaporeans have mixed feelings about Mr Lee.

"We simultaneously love and hate, respect and despise, cherish and abhor, the man," he wrote in a column on the Asian Correspondent website.

"We are thankful for our decades of economic progress but we wonder whether it was really necessary to sacrifice our freedoms," he wrote.

"We are grateful for the stability and security but we wonder whether we can maintain it would a strong civil society."

Mr Tan wrote that Singaporeans can now honor their founding father by "asking tough questions, making hard choices and imagining a different Singapore".

Lindsay Murdoch was based in Singapore from 1989 to 1996.