Afghanistan's government is considering restoring stoning for adultery, a punishment used by the Taliban during its time in power.
"Men and women who commit adultery shall be punished based on the circumstances to one of the following punishments: lashing, stoning [to death]," states article 21 of a draft of the new penal code.
Article 23 of the draft, being drawn up by the ministry of justice, specifies that the stoning should be public.
Unmaried adulterers would face 100 lashes under the changes.
The revision would need to be approved by parliament and the president of Afghanistan for it to become law. Under current laws, adulterers face long prison terms.
Brad Adams, the Asia director for Human Rights Watch, condemned the plan and called on the president, Hamid Karzai, to reject the plan.
"It is absolutely shocking that 12 years after the fall of the Taliban government, the Karzai administration might bring back stoning as a punishment," he said Brad Adams.
"President Karzai needs to demonstrate at least a basic commitment to human rights and reject this proposal out of hand."
HRW said that $16 billion in aid promised to Afghanistan last year was tied to progress on human rights issues.
"Donors need to make clear that international support to Afghanistan's government is not a blank cheque," Adams said.
In Afghanistan, an extremely conservative Muslim country, extramarital sex and sex before marriage are taboo and can lead to bloody conflicts between families.
Stoning was widely practised during the years of Taliban rule, and is used in areas still controlled by the movement. In July last year, a 21-year-old woman was stoned to death in a Taliban-controlled village just 60km north of Kabul.