KUALA LUMPUR - In Singapore, four people have been jailed and two investment banks shut down with other banks fined over their role in the alleged laundering of billions of dollars from state fund 1Malaysia Development Berhad (1MDB).

And just hours before Malaysian Prime Minister Najib Razak held a closed-door briefing for Umno leaders on Tuesday (Dec 5), the United States' Attorney-General called the US$4.5 billion (S$6.1 billion) allegedly siphoned from 1MDB "kleptocracy at its worst".

But the ruling party's rank-and-file say they are confident that no crime had been committed. Umno president Datuk Seri Najib had denied that some US$700 million found in his accounts in 2013 were from 1MDB.

Instead, they are focused not just on returning him as premier after an election due by August, they want to reclaim the two-thirds supermajority they ceded a decade ago.

Never mind that apart from Singapore and the US, authorities in Switzerland, Luxembourg and Hong Kong are among those also probing the claimed theft of public funds allegedly used to buy luxury homes, expensive paintings and a yacht.

The Umno faithful either cite lack of evidence, or argue that any wrongdoing involving the state investor controlled by Datuk Seri Najib was committed on foreign soil, presumably by foreigners.

"Corruption is normal in other countries, whereas in Malaysia, we take it very seriously. So I'm confident it's not happening here. Whatever news on 1MDB... you should take it with a pinch of salt," said young women's (Puteri) wing member Zainab Jaafar from Terengganu state.

Damning headlines both at home and abroad are part of a campaign to undermine and distract Umno, according to Negeri Sembilan divisional youth permanent chairman Mohd Haidil Mohamad.

"We are still looking for exactly who is involved and if there is concrete evidence, we will not defend anyone who is involved, even if it is the Prime Minister. But so long as there is no conclusive proof, we cannot accuse anyone," he told The Straits Times.

This huge gap in perception is perhaps best explained at how Umno and the Malaysia government have dealt with past scandals involving its leaders.

Like the 1MDB affair that was aired at the Umno assembly two years ago, there was a 2005 scandal that was also raised involving approved permits (AP) for importing cars linked to former trade minister Rafidah Aziz.

In 2012, there was some debate at the annual meeting about the so-called cows-and-condos affair involving another former minister and current Women's Chief Shahrizat Abdul Jalil.

Both scandals allegedly resulted in multi-million dollar losses to government coffers. But after some months of angst in the party and media, the issues were shrugged off and buried. Coincidentally, both politicians also continued to lead the women's wing.

And just last week, a government-backed inquiry announced that RM31.5 billion was lost in foreign exchange trading by the Malaysian central bank in the 1990s when Tun Mahathir Mohamad was prime minister. Although the amount lost is far higher than previously disclosed, Dr Mahathir had also continued as Umno president for a decade after the losses.

Umno supporters seem to be guided by their leaders' explanations, rather than global headlines on 1MDB's controversial dealings.

Information chief Annuar Musa told reporters "a lot of people misunderstand that" the US, Singapore and other countries such as Switzerland and Luxembourg "acted in the context of breaking laws within their own countries, not on the issue of 1MDB".

He parroted PM Najib's message that while there were mistakes made, "we know 1MDB is doing well" as its projects such as the Tun Razak Exchange and Bandar Malaysia are on their way to fetch RM140 billion or more in development value.

No leader or delegate has raised 1MDB so far in this year's general assembly. No one raised the issue at last year's meeting either.

Yet when quizzed about the US trying to reclaim as much of the US$4.5 billion it alleges was stolen, several Umno delegates agree that the money should be returned to Malaysia. "Seizing assets is one way to find back the money," said Johor womens' wing delegate Indrakesumawati Abdullah, who added "the government always has the answer".

As Perlis delegate Azimah Mahmud says, "even if there was any wrongdoing, we shouldn't quickly jump the gun... everyone makes mistakes. Don't turn a blind eye on all the good things that (Najib's) done just because of one mistake."