The penal code in the two small slivers of land on Borneo will fully come into force following years of delays and include the amputation of hands and feet for thieves.
Other new laws outlaw adultery and sodomy, whether between two men or an unmarried heterosexual couple, which can be punished by stoning to death or 100 lashes.
Those accused of sodomy must admit the charges or at least four eyewitnesses need to testify.
If a “sodomite” is convicted using other evidence, they still face 30 lashes and up to seven years in jail.
Lesbians face 40 lashes and up to 10-year prison terms.
Non-Muslims are subject to the same punishments for adultery or sodomy if their partner is Muslim but it is currently unclear if two non-Muslims would be punished.
The tiny oil state with a population of around 40,000 run by the autocratic Sultan Hassanal Bolkiah will become the first East Asian state to have a sharia penal code at the national level.
The laws in the former British protectorate were condemned by the United Nations as “cruel and inhumane” and actor George Clooney and pop star Elton John are calling for a boycott of Brunei-owned hotels. Former US vice president Joe Biden and actress Jamie Lee Curtis have also condemned the laws.
Michael Kirby, the co-chairman of the human rights institute of the International Bar Association, said: “It is a horror story that contemporary rulers are even considering restoration of these shocking punishments.
“It is an affront to universal human rights involving cruel, unusual and degrading treatment and punishment. The civilised world will not be silent in the face of these reports from Brunei.”
The defiant Brunei government said in a statement that it “enforces its own rule of law” and sharia “aims to educate, respect and protect the legitimate rights of all individuals”.
The sultan, who also acts as prime minister, is one of the world’s wealthiest men and lives in a vast, golden-domed palace. He first announced plans for the penal code in 2013.
The first phase was introduced in 2014, including less stringent fines or jail terms for indecent behaviour, failure to attend Friday prayers and unmarried pregnancies.
Phil Robertson of Human Rights Watch said: “This kind of law doesn’t belong in the 21st century. It’s going to be something that will turn Brunei into a human rights pariah.”
The Dorchester in London is owned by Brunei. Picture credit: Wikimedia