Muslims may be banned from drinking the world's most expensive coffee - extracted from the dung of a civet cat - over concerns it is unclean.

Maruf Amien, acting head of Indonesia's powerful Ulema Council, said a ruling on the ban could be made tomorrow. He said the key issue was whether or not the Kopi Luwak coffee is clean.

It is made from hard beans that have been eaten and then fermented in the animals' stomachs before being excreted and roasted. It's highly prized for its smooth flavour and bitterless aftertaste, sometimes fetching well over £130 a pound online.

"God willing it will be an easy decision," said Amien. "If the farmers clean the beans before they are grinded, they are halal, or legitimate, and there won't be a problem."

Kopi Luwak is produced on several Indonesian islands, from Sumatra in the west to Sulawesi in the east, but it also can be found under different names elsewhere in Southeast Asia. Only 1,000lbs are said to be produced annually worldwide.

Indonesia is the world's most populous muslim nation. The influential Ulema Council often issues fatwas, or edicts, including several controversial rulings against smoking and yoga. Its edicts are not legally binding, but many devout muslim abide by them.