The World Wide Fund for Nature says some musk deer populations could be driven out of existence by the demands of the international perfume trade.

The BBC's Margaret Gilmore: "160 have to be killed for every kilogram of musk"

The musk deer is a small, solitary and very shy animal that lives in the mountainous forests of Asia and eastern Russia. Its total numbers are put at somewhere between 400,000 and 800,000 animals.

The populations of Afghanistan, Bhutan, India, Myanmar, Nepal and Pakistan are listed on Appendix 1 of CITES (the UN Convention on International Trade in Endangered Species), which forbids all international trade.

All other musk deer populations are listed on Appendix 2, which allows limited trade.

'Massive decline'

A report by WWF-UK and Traffic (the wildlife monitoring programme of WWF and the International Union for the Conservation of Nature) says the species is undergoing "a massive decline".

Raw musk is taken from the male animal's "pods", or scent glands

The problem is the demand for natural musk in the perfume trade and in traditional Chinese medicine, where it is used in making preparations designed to strengthen the bones.

The report, entitled "On the Scent", says some populations are now seriously decreasing, and if the threats remain unchecked the deer could disappear altogether.

It says musk remains one of the most expensive natural products in the world, three to five times more valuable than gold at up to $45,000 a kilogram.

Scent glands

The raw musk is taken from the male animal's "pods", or scent glands, but the report says that from three to five deer are usually killed before the hunters can find a single male who will yield about 25 grams.

Stuart Chapman, WWF: EU must step in to enforce veto

It says this means about 160 deer are killed for each kg of musk that is collected. And other species, including the giant panda, stray into the snares intended for the deer.

WWF-UK's international conservation officer, Stuart Chapman, says: "The snares set by poachers for musk deer kill indiscriminately".

"Consumers of perfumes have no way of knowing what they are buying, and manufacturers should come clean and clearly label their perfumes.

"In Europe alone, the amount of raw musk legally imported in the past two decades represents the loss of tens of thousands of wild musk deer, and imports seem to be increasing."

Famous houses

The report says Russian musk deer populations have fallen by 50% in the last ten years because of poaching and over-exploitation.

The BBC has been unable to confirm which perfume houses still use natural musk

It says the use of natural musk is linked to some of Europe's best-known perfume makers, WWF says a couple of the houses have acknowledged that they do use musk in a few traditional and expensive perfumes. But it believes the directors of the perfume houses "are unaware of the consequences of their actions on wild musk deer populations".

WWF wants the European Union and the perfume industry to suspend imports of wild musk from the Russian Federation until more research is carried out on the deer populations. It says substitutes could be developed.