Scandal-hit Malaysian Prime Minister Najib Razak is moving to shore up support in the country's Malay-Muslim heartland as a nationwide campaign backed by almost 100 non-government-organisations gets under way to try to force him from office.

Mr Najib has been willing in the past to stoke nationalist and Islamist sentiments for the sake of his own political career and that of his long-ruling United Malays National Organisation.

He could see some political gain in his government taking a hard line against Australians who were obviously having fun at the end of the grand prix without thinking through the consequence of their actions in the deeply conservative nation.

Charges including disrespecting Malaysia's flag could see them sentenced to serious jail time. Their predicament is potentially worse as they have been widely reported by Malaysian media as having stripped to their underwear, a further cultural offence.

Mr Najib's reputation internationally is in tatters after hundreds of millions of dollars turned up in his private bank account as revelations swirled around the heavily indebted state-owned sovereign fund 1Malaysia Development Berhad (1MDB), which he set and oversaw through an advisory committee.

The pro-democracy and clean government group Bersih is planning an anti-Najib rally on November 19.

Previous rallies have met with a heavy-handed response from Mr Najib, the British-educated son of a former prime minister who has had strong links with successive Australian governments.

Mr Najib should have lived up to the democratic traditions he claims Malaysia adheres to. He should have stepped aside months ago while investigations are completed in multiple countries into the alleged misappropriation of billions of dollars of 1MDB funds.

But the Prime Minister, who denies any wrongdoing, now appears to be gearing up for an early election, possibly in the second half of next year.

He has been able to maintain a firm hold on power, despite the allegations against him, with the support of the division chiefs of UMNO who have for years benefited from the party's largesse and an entrenched system of money politics.

Malaysia has in the past deported foreigners who have upset local cultural or political sensitivities, including ABC reporter Linton Besser and camera operator Louie Eroglu who were detained in March in the city of Kuching after Mr Besser had dared ask Mr Najib questions about the 1MDB scandal.

The best the Australians can hope for seems to be that after four days in jail they will be escorted to Kuala Lumpur International Airport and deported back to Australia but what happens to them is in the hands of a Malaysian leader fighting for his political life.