The leopard skin was seized from two men in a bike from NH-31 at Birpara in West Bengal's Jalpaiguri district following a tip off.
The skin was packed in a bag and was being taken to Nepal to be sold, police said.
One of the two accused hailed from Darjeeling and another from Bhutan.
Their three accomplices who were in a car managed to flee.
Baikunthapur forest ranger Sanjay Dutta said clouded leopards are rare in north Bengal and are found mostly in Bhutan.
