More than 40 percent of the smuggling cases heard by a Beijing court in the past few years involved products made from precious animals, it said on Thursday.

The Beijing No 4 Intermediate People's Court is responsible for handling all smuggling cases in the capital. According to the court, 73 of the 166 cases it heard from Jan 1, 2015 to June 30 this year were related to precious animal goods.

Most defendants were migrant workers overseas and Chinese travelers, and they were mainly accused of smuggling products including ivory, rhino horns and pangolin skins, according to Wang Jing, chief judge of the court's criminal division.

"They were often found putting the products in their luggage or carrying them while reentering the country," he said. "Some were looking to sell them for profit, while others wanted to send them to friends as gifts or for curing diseases."

In one of those cases, a defendant surnamed Li was discovered carrying four bags of pangolin skins in his luggage when he arrived at Terminal 3 of the Beijing Capital International Airport from overseas on Jan 19, 2019.

The court said the value of the skins was more than 275,000 yuan ($42,580), but it did not say what country Li had returned from.

It said Li was later sentenced to 2.5 years in prison and was fined 25,000 yuan for smuggling.

Wang estimated that such crimes will still account for a large proportion of the court's cases, "which means protecting biodiversity and ecological security will be a long-term challenge".

Moreover, the court also heard a number of drug smuggling cases, as well as others in which people evaded taxes by smuggling general goods during the aforementioned period.