The customs department seized dried seahorses worth around Rs 56 lakh and detained two traders at Nathu-la on the India-China border in Sikkim on Tuesday.

Customs officials said the consignment had been impounded following a tip-off and was bound for China.

“We had received a tip-off and accordingly, checked a vehicle on the border bearing a registration number plate of China. Around 56kg of seahorse was found. We have detained two traders who are based in Sikkim and are into border trade with China. They would be interrogated to obtain more details,” said a source in the department.

The seahorses were packed in a carton and have been brought from Calcutta by train.

“It was brought from Calcutta to New Jalpaiguri by train. From there, the consignment was taken to Sikkim by road and was put into the vehicle so that it could be smuggled into other side of the border,” the source said.

The customs department has estimated the cost of the seized item to be around Rs 56 lakh but is yet make a final assessment.

According to the International Union for the Conservation of Nature (IUCN), there are around 40 species of seahorses. Among them, some of the species are considered to be vulnerable or endangered and all are protected by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).

“There is a huge demand of seahorses in countries like China and Taiwan where they are used in making traditional medicines,” said a senior forest official.

The customs officials have also communicated with the Sikkim forest department about the seizure, said Tshering Wangdi Lepcha, the state forest minister. “They have intimated us. We are yet to take possession of the seized consignment,” said the minister.