Opponents of polygamy in Muslim-majority Malaysia said Thursday they will conduct a rare survey in an attempt to prove the practice throws families into emotional and economic turmoil.

Researchers hope to interview 6,000 members of polygamous households over the next 10 months in what could be the most comprehensive survey ever conducted on polygamy in a Muslim society, said Zainah Anwar, director of Sisters In Islam, a Malaysian women's rights group.

"We need evidence-based material to strengthen our advocacy for awareness and reforms, rather than merely use stories or assumptions about polygamy," Zainah said at a news conference.

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Islam allows a man to have up to four wives. The practice of polygamy has sparked debate in Malaysia, where nearly 60 percent of the nation's 26 million people are Muslim, because activists say some polygamous husbands neglect their responsibilities to wives and children.

According to government statistics, there were about 13,500 polygamous marriages in Malaysia between 1995 and 2004, or about 1.4 percent of all Muslim marriages, said Norani Othman, a sociologist at the National University of Malaysia.

However, anti-polygamy activists believe the true number is higher because many men fail to report their second or third marriages in order to keep them a secret from their primary families.

Polygamy is illegal for Malaysia's non-Muslim minorities, who are mainly Buddhists, Christians and Hindus.

The new study is significant because recent surveys on polygamy in other Muslim countries have only included a small number of respondents and focused on legal issues, not the financial and social impact of the practice, Norani said.

Researchers plan to ask polygamous families a wide range of questions, including how their expenditure for clothes and other necessities is affected when the man marries another wife, and whether existing wives and children are forced to make financial sacrifices.

The survey will cover other everyday dilemmas, including how husbands divide their time among multiple wives, celebrate holidays and choose which wife to take to social functions. It will also consider whether current laws sufficiently safeguard wives from mistreatment.

Sisters in Islam is aiming to publish its findings in early 2008.

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