MARK COLVIN: The prime minister of Singapore is suing a jobless blogger for defamation.

It's an old tactic in Singapore to silence dissent. But this time there's been an unexpected twist.*

Citizens have rallied publicly in support of the accused blogger, and donated more than $100,000 to help fight the case in the courts.

Peter Lloyd reports.

PETER LLOYD: Until a few years ago Roy Ngerng lived the quiet life in Singapore. He had a job in a public hospital, and relative anonymity.

That all changed when he started blogging about what he saw as injustice and unfairness in Singapore.

He's written about 400 articles.

But one in recent weeks crossed the invisible barrier in Singapore locals calls the 'OB' marker: out of bounds.

ROY NGERNG: I have written an article which discuses how the retirement funds in Singapore are being used to be invested.

PETER LLOYD: In Singapore they don't have superannuation. The compulsory state saving scheme is called the Central Provident Fund, CPF.

In his article, Roy Ngerng questioned the rate of return the government gives workers after investing their contributions.

ROY NGERNG: Currently the investment funds are earning 6.5 to 16 per cent. But for Singaporeans with retirement funds we are only earning 2.5 to 4 per cent.

So my argument is that if investment firms are earning such a high interest and Singaporeans are earning such low interest, then there must be some transparency and accountability as to how our retirement funds are being used.

PETER LLOYD: It sounds innocuous enough - a call for transparency, says Roy Ngerng.

But that's where the OB marker lies in wait.

The body that invests Singaporeans money for them has as its chairman the prime minister.

So Lee Hsien Loong took personal offence at the call for more transparency. His lawyer said the article accused the PM of 'criminal misappropriation'.

Roy Ngerng backed down fast. He removed the offending post, apologised, and offered Mr Lee $5000 in damages.

But the offer was dismissed as 'derisory'.

PETER LLOYD: Are you surprised that you were sued for defamation by prime minister Lee Hsien Loong?

ROY NGERNG: Well you know last year they came up with MDA licensing rule, where they say that if the government is not agreeable with any article that you put up, they will ask you to take it down or, and to pay a performance bond of fifty-thousand Singapore dollars. So I expected that at some point I will be subjected to that rule, to have to take it down. But to be sued is beyond my current expectations, I will say that I will be more disappointed than, I would rather the government engage citizens or the citizens who are asking them key questions on the retirement funds to actually let us see the transparency reports and to engage us in conversation and then we can then decide, based on the information that we know, we think that these are the solutions that should be done.

I think it's better that, instead of the government telling us and scaring us.

[Crowd cheer]

PETER LLOYD: But the scare this time may have been in the government's ranks.

Six thousand people turned up to support Roy Ngerng at this public rally.

And in what's probably an even greater second shock, many of those demonstrators have put money where their mouths are.

Via a crowd sourcing platform online, more than $100,000 has been raised to pay the legal bills for a fight with the prime minister in the courts. The first hearing is in July.

Roy Ngerng is settling in for a long battle.

ROY NGERNG: I think Singaporeans are frustrated that for a very long time, for more than the past 10, 20 years, we have been giving the feedback to the government on the CPF, the retirement funds and it has fallen on deaf ears. And the government hasn't responded as much as it should and the solutions that the people want have not been heard.

So I think they see this as an opportunity for them to be able to speak up, perhaps using me as a platform, but to be able to at least have their voice heard.

PETER LLOYD: That may be but Roy Ngerng is in the government's cross hairs. The state run hospital that employed him let him go last week. If there was any doubt that it was politically motivated the government itself provided the answer when the minister for health himself made it his business to announce the sacking of a low level patient co-ordinator.

MARK COLVIN: Peter Lloyd.

*EDITOR'S NOTE (19 June 2014): This transcript has been amended after the original version incorrectly stated Roy Ngerng faced charges of criminal defamation and a possible jail term. Mr Ngerng in fact faces a civil lawsuit which does not carry the threat of imprisonment.