A controversial law in Afghanistan that includes a provision making it illegal for a Shia Muslim woman to refuse to have sex with her husband cannot be changed, one of the drafters of the legislation said.

The comments by Mohammad Asif Mohseni, a top Afghan cleric, seem to contradict the message from Canada's foreign minister, who said Afghan justice officials were going to delete contentious clauses.

Mohseni told reporters in Kabul on Saturday that the legislation cannot be changed because it passed by both houses of parliament and was signed by Afghanistan President Hamid Karzai.

But last week, Lawrence Cannon said the legislation is under review by the Department of Justice in Afghanistan and that assurances for the changes came from Afghanistan's foreign and interior ministers.

Karzai himself said the law will be studied and may be sent back to parliament.

The law says a husband can demand sex with his wife every four days unless she is ill or would be harmed by intercourse, and regulates when and for what reasons a wife may leave her home alone. The legislation has sparked international outrage.

Mohseni said that women and men are not equal in Afghanistan and shouldn't be treated as equals, arguing that men are the breadwinners and that rural women are illiterate, making it difficult for them to provide financial support to the family.

"It is not possible for all women to pay the same amount of money as men are paying. For all these expenses, can't we at least give the right to a husband to demand sex from his wife after four nights?" he said.

Mohseni defended the legislation, saying a woman can refuse sex with her husband if she is fasting for Ramadan, preparing for a pilgrimage, menstruating, or has just given birth.

But he stressed that "it is essential for the woman to submit to the man's sexual desire."

"If she is not sick, and if she does not have another problem, it is the right of a man to ask for sex and she should make herself ready for it. This is the right of a man," Mohseni said.

He suggested that those who support democracy in Afghanistan should allow it to prevail, even if they don't like the outcome.

"The Westerners claim that they have brought democracy to Afghanistan. What does democracy mean? It means government by the people for the people. They should let the people use these democratic rights," he said.

With files from the Associated Press