In Nigeria, women's rights groups and human-rights activists are working to appeal the conviction of a woman sentenced to death by an Islamic court for committing adultery. She has a stay of execution until her case is reviewed Monday by an appeals court.

Unless the ruling is overturned, the 35-year-old divorcee and mother of five will be put to death as soon as she weans her 11-month-old baby. The traditional method would place Sufiyatu Huseini in a pit or tied against a tree or pillar, unable to escape a rain of stones, each legally mandated to be no bigger than a fist.

Beginning Monday, her case will be heard by an Islamic court of appeals in the northern Nigerian town of Sokoto. Neither supporters nor critics of Islamic law, Sharia, can be sure how the appeals case will turn out. Although Sharia has been used for decades in civil courts, it is only in recent months that northern Nigerian states have been using it in criminal cases.

Northern Nigeria follows one of Islam's strictest forms of jurisprudence, the Maliki school of Sharia. Under it, some scholars argue that pregnancy is sufficient proof to condemn a woman of adultery.

But they say more evidence is needed to convict the neighbor she says raped her, Malam Yakubu Abubakar. He denies the charge and was acquitted for lack of evidence by Judge Alhaji Mohammed Bello. State prosecutors say that to convict Mr. Abubakar, Islamic law requires either that he confess or that at least four witnesses attest to the crime.

Human-rights activists say that standard makes it nearly impossible to convict a man of adultery.

Ms. Huseini's defenders say she should not have been found guilty of adultery. They concede that Ms. Huseini did not complain of rape while admitting to intercourse with Mr. Abubakar during her trial. But they say she was not aware of her rights, including her right to a lawyer and the right to not incriminate herself.

Her defenders are pinning their defense on these and other alleged irregularities during the trial. And they challenge the assertion by many scholars that pregnancy in itself is proof of adultery, and the fact that the requirement for four witnesses applies only to men.

Mufuliat Fijabi is a program officer for an Abuja-based women's rights group called BAOBAB. "Sofiya is divorced, and if you look at the case properly, there is no reason why she should have been convicted of adultery in the first place. The Koran says with respect to adultery there must be four witnesses [who have] seen the people concerned. In the absence of that, you can not convict for adultery; in her case, pregnancy has been used as evidence. But there were no witnesses [who saw] the act.

Disagreeing with Ms. Fijabi is Judge Bashir Sambo, a former Grand Kadhi, or judge, of the Sharia Court of Appeals in the Federal Capital Territory, Abuja. He says it is up to Ms. Huseini to convince the appeals court judge that her pregnancy was due to rape, especially since she did not mention any assault in her trial.

"She can explain to the court, and then it is up to the court to decide. If the appeals court feels there is an element of truth, that she was raped or forced into committing adultery, she will not be penalized and condemned to death by stoning at all.

There might be people around who could be invited who might know how she was lured to go wherever she went [for sex]; she could explain that if she had not done so before. She would not need four witnesses [to back up her story]; two would be enough.

And, Judge Sambo says Sharia does not require the judge to alert Ms. Huseini of her right to a lawyer, or to any other rights. He says that is a misunderstanding among Muslim lawyers who are schooled in Western law.

A.B. Mahmoud is a Muslim laywer, and a former attorney general of Kano State. He disagrees with Judge Sambo. Mr. Mahmoud says it is not up to Ms. Huseini to prove she was raped, but rather it is the responsibility of the prosecution to prove that the intercourse that took place was indeed adultery.

"I believe opinions on this matter will differ a lot, but the Koranic injunction upon which this matter is based clearly does not place the burden of proof on the accused person, the suspect," he said.

"The injunction speaks of four witnesses. If the prosecution is not able to produce four credible witnesses then the question of shifting the burden to the woman would not be in accord with Islamic law and under the Koran. [Also,] pregnancy itself could prove that intercourse has taken place. But that is a totally different issue: circumstances are extremely important under which this intercourse takes place. The woman can have complete defense if the intercourse takes place under certain circumstances. But the whole issue is pregnancy itself can not prove all the circumstances, and the prosecution still has the burden in my view to establish that what took place was consensual sex by a married woman with another man. And that is the crux of the issue: it is not the pregnancy, it is that the sexual intercourse took place under circumstances that the law considers adultery, and that is the burden of the prosecution."

Mr. Mahmoud says if the prosecution can not prove that the type of intercourse that took place is adultery, all charges against Ms. Husseini should be dropped.

Mr. Mahmoud agrees with those who say Ms. Huseini may not have received a fair trial, and that this could be a reason for the appeals court to reduce her penalty. He concedes that Islamic law does not provide for the defendant to be warned of his or her rights to a lawyer, or to other protections, but he says the Nigerian constitution under which the Sharia courts operate, does.

"Under the [secular] Nigerian constitution she is entitled to counsel, and she will still be subject to those rights and protections, so it can not be argued that it is not the responsibility of a judge to explain this, especially where the punishment is capital punishment," he said. "She will be entitled to all the constitutional protections accorded under Nigerian law."

Mr. Mahmoud says if the appeals court does not decide in favor of the defendant, Ms. Huseini still has two more courts in the federal system she can appeal to.

The case is being watched by another woman recently accused of adultery. This past week, Hafsatu Abubakar was arraigned in the Sokoto Sharia court for also having a child out of wedlock. Like Ms. Huseini, the man in the case has denied the charges and is not being tried. If it can be proved that Ms. Abubakar has ever been married, she, like Ms. Huseini, may be sentenced to death by stoning. If she has not been married, the new mother faces 100-lashes with a cane.