Pushing through sharia punishments ... Brunei Sultan Hassanal Bolkiah, centre, is welcomed by a guard of honour in Singapore.

Pushing through sharia punishments ... Brunei Sultan Hassanal Bolkiah, centre, is welcomed by a guard of honour in Singapore. Photo: AP

Bandar Seri Begawan, Brunei: A controversial new penal code for oil-rich Brunei that will eventually include tough Islamic sharia penalties such as severing of limbs and death by stoning was due to officially come into effect on Thursday.

Brunei's all-powerful Sultan Hassanal Bolkiah had announced on Wednesday that he would push ahead with the introduction of the new criminal code that has sparked rare domestic criticism of the fabulously wealthy ruler and international condemnation.

The initial phase beginning on Thursday introduces fines or jail terms for offences including indecent behaviour, failure to attend Friday prayers, and out-of-wedlock pregnancies.

There were no known events to mark Thursday's implementation.

A second phase covering crimes such as theft and robbery is to start later this year, involving more stringent penalties such as severing of limbs and flogging.

Late next year, punishments such as death by stoning for offences including sodomy and adultery will be introduced.

The sultan - one of the world's wealthiest men - had announced the implementation last year.

He first called for the penal code in the late 1990s and has increasingly voiced plans to strengthen Islam's role in the already conservative, energy-rich Muslim country on Borneo island.

But the plans by the revered father-figure monarch triggered unprecedented criticism earlier this year on Brunei's active social media, though the move appears to enjoy broad support, especially among Muslim ethnic Malays, who make up about 70 per cent of the population.

The UN's human rights office and various international rights and legal activist groups also have condemned the move as out of step with modern society.

Brunei is the first country in East or Southeast Asia to introduce a sharia penal code on a national level, joining several mostly Middle Eastern countries like Saudi Arabia and Iran.

Attorney General Hayati Salleh late on Wednesday sought to ease concerns over the code's implementation, stressing that sharia cases will face high burdens of proof before the tough penalties are imposed.

"It is crucial that we, and the international community, understand these distinctions and not focus solely on the punishments but rather, on the evidence-gathering process that is complicated and strict," she said.

The monarch's wealth - estimated three years ago at $US20 billion ($21.59 billion) by Forbes magazine - is legendary with reports of a vast collection of luxury vehicles and huge, gold-bedecked palaces.

The monarchy was deeply embarrassed by a sensational family feud between Hassanal and his younger brother Jefri Bolkiah over the latter's alleged embezzlement of $US15 billion ($16.19 billion) during his tenure as finance minister in the 1990s.

Court battles and investigations revealed salacious details of Jefri's un-Islamic jet-set lifestyle, including allegations of a high-priced harem of Western women and a luxury yacht he owned called "Tits".

AFP