Indonesia's top Islamic clerical body has issued a religious fatwa against the illegal hunting and trade in endangered animals in the country, which the WWF hailed on Wednesday as the world's first.

The fatwa by the Indonesian Ulema Council declares such activities "unethical, immoral and sinful", council official Asrorun Ni'am Sholeh told AFP.

"All activities resulting in wildlife extinction without justifiable religious grounds or legal provisions are haram (forbidden). These include illegal hunting and trading of endangered animals," said Sholeh, secretary of the council's commission on fatwas.

"Whoever takes away a life, kills a generation. This is not restricted to humans, but also includes God's other living creatures, especially if they die in vain."

The country of 250 million people is the world's most populous Muslim nation, but it remained unclear whether the fatwa would have any practical impact.

Indonesia's vast and unique array of wildlife is under increasing pressure from development, logging and agricultural expansion.

The government does not typically react to fatwas by implementing specific policy changes.

However, a Forestry Ministry official who asked to remain anonymous told AFP the ministry and the religious council would make a joint announcement regarding the fatwa on March 12, without elaborating on its content.

The WWF called the fatwa the first of its kind in the world, and said the use of religion for wildlife protection "is a positive step forward."

"It provides a spiritual aspect and raises moral awareness which will help us in our work to protect and save the remaining wildlife in the country such as the critically endangered tigers and rhinos," WWF Indonesia communications director Nyoman Iswara Yoga said.

The fatwa was the result of months of dialogue between government officials, conservationists and other stakeholders, said Sholeh, the fatwa commission official.

Acknowledging it was not legally binding, Sholeh said in English: "It's a divine binding."

He said the fatwa was effective from January 22. It was only made public late Tuesday.

The fatwa urges the government to effectively monitor ecological protection, review permits issued to companies accused of harming the environment, and bring illegal loggers and wildlife traffickers to justice.

The clearing, often illegally, of Indonesia's once-rich forests for timber extraction or to make way for oil palm or other plantations poses a severe threat to critically endangered species such as the Sumatran tiger, orangutan, and Sumatran elephant.

Poachers also target wild elephants for their ivory tusks, for use in traditional Chinese medicines.

Under Indonesian law, trafficking in protected animals can result in a maximum of five years in jail and 100 million rupiah ($8,700) fine.