Chinese customs authorities said they seized 156 prehistoric mammoth tusks from a truck entering from Russia in one of the country's largest such hauls.

The contraband was seized in late April at a border crossing in northeastern China's Heilongjiang province bordering on Siberia, but the find was only announced this week by Chinese customs, state media said.

The haul, which also included two elephant tusks and a range of other animal parts, was hidden under a shipment of soybeans.

Eight suspects, including Russians and Chinese, have been arrested, the People's Daily said.

China banned the sale and processing of elephant ivory last year after having banned its import in 2015. 

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This, along with global efforts to stamp out the ivory trade to save elephants from extinction, have led smugglers to turn to a stock of ancient mammoth tusks buried mostly in Siberia but also Europe and North America.

The People's Daily said the shipment as a whole was one of China's largest involving animal parts in recent years.

The official Xinhua news agency said the inventory included "two elephant tusks, 1,276 antelope horns, 156 mammoth tusks, 406 walrus tusks, 226 narwhal tusks, as well as gall bladders and bear teeth and 320 kilos of sea cucumbers."

A wide variety of animal parts are sought after in China as traditional medicines or for other uses, while ivory carving is an ancient art in the country.

The latest seizure's estimated value was 106 million yuan ($15.7 million), Xinhua said, adding that an investigation was under way.