KABUL, Afghanistan – An Afghan man facing a possible death penalty for converting to Christianity from Islam may be mentally unfit to stand trial, a state prosecutor said yesterday.

Abdul Rahman, 41, has been charged with rejecting Islam, a crime under this country’s Islamic laws. His trial started last week and he confessed to becoming a Christian 16 years ago. If convicted, he could be executed.

But prosecutor Sarinwal Zamari said questions have been raised about his mental fitness.

“We think he could be mad. He is not a normal person. He doesn’t talk like a normal person,” he told the Associated Press.

A religious adviser to President Karzai, Moayuddin Baluch, said Mr. Rahman would undergo a psychological examination.

“Doctors must examine him,” he said. “If he is mentally unfit, definitely Islam has no claim to punish him. He must be forgiven. The case must be dropped.”

It was not immediately clear when he would be examined or when the trial would resume. Authorities have barred attempts by the AP to see Mr. Rahman and he is not believed to have a lawyer.

A Western diplomat in Kabul and a human rights advocate – both of whom spoke on condition of anonymity because of the sensitivity of the matter – said the government was desperately searching for a way to drop the case because of the reaction it has caused.

America, Britain, and other countries that have troops in Afghanistan have voiced concern about Mr. Rahman’s fate.

The Bush administration Tuesday issued an appeal to Kabul to let Mr. Rahman practice his faith in safety. German Roman Catholic Cardinal Karl Lehmann said the trial sent an “alarming signal” about freedom of worship in Afghanistan.

The case is believed to be the first of its kind in Afghanistan and highlights a struggle between religious conservatives and reformists over what shape Islam should take there four years after the ouster of the fundamentalist Taliban regime.

Afghanistan’s constitution is based on Shariah law, which is interpreted by many Muslims to require that any Muslim who rejects Islam be sentenced to death. The state-sponsored Afghanistan Independent Human Rights Commission has called for Mr. Rahman to be punished, arguing he clearly violated Islamic law.

The case has received widespread attention in Afghanistan where many people are demanding Mr. Rahman be severely punished.

“For 30 years, we have fought religious wars in this country and there is no way we are going to allow an Afghan to insult us by becoming Christian,” said Mohammed Jan, 38, who lives opposite Mr. Rahman’s father, Abdul Manan, in Kabul. “This has brought so much shame.”

Mr. Rahman is believed to have converted from Islam to Christianity while working as a medical aid worker for an international Christian group helping Afghan refugees in the Pakistani city of Peshawar.