Video released by China Customs shows the live snakes packed into bags. Photo: China Customs

The unnamed traveller was stopped after passing through the "nothing to declare" gate at the crossing between semi-autonomous Hong Kong and the city of Shenzhen, officials said.

Upon inspection, he had 104 snakes in “six canvas drawstring bags" inside his trousers, a statement from China Customs said.

“Each bag was found to contain living snakes in all kinds of shapes, sizes and colours,” it added.

Video released by Chinese customs shows a pair of agents peering into transparent plastic bags filled with live red, pink and white snakes.

They were mostly small, but it is a large and squirmy haul of slithering reptiles for anyone to carry in their trousers.

Strict biosecurity and disease control laws forbid people from bringing in non-native species without permission into the country.

“Those who break the rules will be… held liable in accordance with the law,” the customs authority said, without specifying the man’s punishment.

In 2023 at the same crossing point, a woman was stopped trying to smuggle in five snakes hidden inside her bra.

China is one of the world’s biggest animal trafficking hubs and authorities have been cracking down on the shady trade in recent years.