The 49-year-old man, whose name has not been revealed is a native of Quang Ninh Province in northern Vietnam. He has been detained for illegally transporting rare and endangered animals.

Customs officials found his actions suspicious and checked his luggage. The rhino horns were wrapped in aluminum foil and hidden in his luggage.

These horns came from double-horned rhinos in Africa, which are on the list of endangered, precious and rare wildlife species that are not allowed to be hunted, traded, stored or transported under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).

Authorities said they are expanding the investigation. The man has not revealed why he had illegally transported the horns into Vietnam.

International conservation groups have identified Vietnam and China as the world's two major consumers of rhino horns, a charge the two countries have refuted.

Vietnam is a major consumer of rhino horns, with locals believing it has magical medical powers. The country is also transit point for elephant ivory as it heads to mostly Chinese and American consumers for making jewellery and home decorations

Vietnam has banned trade in rhino horns, elephant ivory and pangolins, but weak law enforcement has allowed a black market to flourish, supplying a global multi-billion-dollar industry with animal parts and exotic pets.