The International Commission of Jurists says Brunei’s new penal code, which includes death by stoning for adulterers, would violate human rights.
The sharia penal code, enacted into law last October, is scheduled to come into force in April.
The revised law criminalises adultery, extra-marital affairs, consensual gay sex and also re-introduces the death penalty after years of an effective moratorium.
In a letter to Brunei’s government, the organisation said the new legislation is not compatible with international human rights law.
The ICJ’s international adviser Emerlynne Gil has told Radio Australia’s Asia Pacific women are especially vulnerable.
“Women face more risk of receiving this penalty because they are most likely to be found guilty of adultery or having engaged in extra-marital sexual relations,” she said.
“This is because of the institutionalisation of gender discrimination in the laws.
Ms Gil says the penal code is a backwards step for the country on the road to securing international human rights standards.
“We were very surprised that an ASEAN member is doing this, especially at this point in time, where the ASEAN is trying to demonstrate to the international community that it is able to develop human rights standards,” she said.
“This definitely is a setback, not only for Brunei, but for the entire region.”
Many crimes under the new code have a high burden of proof and sharia court judges would have discretion over punishments, which could also include amputations for theft.
Brunei already enforces Islamic teachings more sternly than Malaysia and Indonesia, banning the sale of alcohol and evangelism by other religions.