Last week's caning display brought home the harsh reality of a penal code which punishes adultery with death by stoning, theft with amputation by the sword and drunkenness with 40 lashes from a rattan cane.
From April, the Muslims who are 70 per cent of Brunei's population of 400,000 will risk all these punishments. And despite the guard's assertion, just three or four strokes of his cane will break the skin and leave most victims scarred for life.
The impending adoption of sharia has led to calls for Britain, Brunei's closest ally, to reassess its relationship with a former protectorate, which won independence in 1984.
"London has a very important role in trying to get the Sultan to reconsider this drastic move to a criminal sharia system," said Phil Robertson, deputy director of the Asia division of Human Rights Watch.
"There needs to be a major international outcry to stop this law and Great Britain should take the lead, starting by raising public concerns at the ... Commonwealth meeting."
Sultan Hassanal Bolkiah, 67, is not used to having his decisions challenged. He is head of state and Prime Minister, as well as Finance and Defence Minister. Ruling in near feudal fashion, the Sultan does not tolerate dissent or opposition political parties.
Armed with the revenues of Brunei's oil and gas reserves, the Sultan is one of the world's richest men and his fortune enables him to pay for a British Army garrison of about 1000 soldiers - mainly a battalion of Gurkhas - which informally guarantees his rule.
His opulent, golden-domed palace in Bandar Seri Begawan is patrolled by former Gurkhas, rather than local troops. The British Army retains a jungle warfare training school in the country.
Sharia is already in use in divorce cases and many local Muslims believe the new penal code is needed to combat a rising tide of immorality. "I think His Majesty feels the need for sharia law is more pressing now because of changes in our society," said one female barrister who asked to be known only by her first name, Diwa. "Many Bruneians study abroad, especially in the UK, and they experience things there and bring them back with them. We are seeing more cases of unmarried pregnant women, of adultery, drinking and drugs. Even the divorce rate is rising."
But few outsiders regard Brunei as a den of iniquity. Alcohol and cigarettes are illegal, there are no nightclubs, few cafes and just four cinemas.
Nonetheless, advocates of sharia believe 100 lashes for couples who have sex outside marriage is the only way to combat pernicious Western influences. "It will be a deterrent to people. I mean, who wants to be stoned to death?" said Diwa.
Brunei is the world's fourth-biggest producer of natural gas, giving the Sultan enough wealth to buy the loyalty of his subjects. There is no income tax, education is free and a visit to hospital costs a token 50p (97c). But some of the Sultan's subjects are not sanguine about the impending arrival of sharia. "A lot of people are talking about the new law and they don't like it," said "Rosmani", 27, an IT worker.
