Despite being extinct for 4,000 years, woolly mammoths could get legal protection.

The move would be made under the Convention on International Trade in Endangered Species (Cites), the Sunday Times reported.

This follows the discovery of mammoth tusks in the Siberian tundra which have emerged as the permafrost has melted because of climate change.

It is estimated that as many as 150 million dead mammoths could lie underneath the tundra, providing a rich harvest in tusk ivory.

Mammoth ivory was seen as an ethical alternative to that derived from elephants.

Currently trading in mammoth ivory is legal but dealing in elephant ivory is not.

Michelle Obama was photographed wearing a mammoth ivory necklace, a move which led to her coming under attack from some conservationists.

They warned that poachers were passing off elephant tusk ivory as having been derived from mammoths to get around existing restrictions.

Moves to bring the laws governing mammoth tusks into line with elephants will be discussed at the Cites conference in South Africa next month.