Officials in north Indian state of Uttar Pradesh say they have arrested four people carrying a large number of tiger and leopard skins.

The chief wildlife conservation official in Uttar Pradesh, Dr Ram Lakhan Singh, said that 74 tiger and leopard skins were recovered from an illegal taxidermy workshop in the town of Khaga, about 150 km south of Lucknow.

Forestry officials also recovered more than 1,800 tiger and leopard nails and over 200 black buck skins.

Mr Singh described it as biggest ever seizure of tiger and leopard skins in India.

He said they had seen no signs of bullet holes and that forestry officials believe the tigers and leopards were killed by poisoning.

Similar cases have been reported in the past, usually when tigers and leopards stray out of reserved forests.

Forestry officials say that poachers take undue advantage of the anger of local people against man-eating tigers.

Tigers, leopards and other endangered animals are protected under the law in India.

The killing of such animals, and the trading of their parts is a crime.

Police say that interrogation of the four people arrested has revealed that after processing, the skins are taken to Delhi, from where they are smuggled to south-east Asian and Gulf countries.

Dr Singh said there is no domestic market for tiger skins because few Indians display these items in their houses.

But in other countries, he said, the display of tiger skins is still considered a matter of pride.

There are also reports that in some south-east Asian countries, tiger parts are used to prepare medicines to enhance peoples' sex lives.

Forest officials say they are now requesting the Central Bureau of Investigation to look into the case because of its national and international links.