People buying animal "souvenirs" have been warned they must check they are legal after police seized a number of crocodile skulls imported from China.
Police are investigating the finds after searching two properties in Machynlleth, Powys, on Wednesday.
Dyfed-Powys Police and North Wales Police said they had found "numerous" skulls across the searches.
Animal trade charity Traffic said importers and buyers must make sure they had the correct permits.
Richard Thomas, from Traffic, said some people would buy things such as skulls as a "talking point".
Trade in some species, including some types of crocodiles, is banned outright, but others can be bought and sold as long as the exporting country issues permits.
Earlier this month, police seized a skull of a critically endangered Siamese crocodile from a man in Chippenham, Wiltshire, after he paid about £30 to a buyer in China.
Wiltshire Police said the man bought it as an "unusual" house ornament and had no idea that it was protected.
No further action was taken against him when police decided he had made an honest mistake.
The Convention on International Trade in Endangered Species of Wild Fauna and Flora is the main worldwide agreement controlling trade in wild animals and plants, and is signed by more than 180 countries.
In 2016, the UN estimated that the annual value of illegal wildlife trade was between $7bn-$23bn (£5.4bn-£17.8bn).
Traffic said demand for such items as horns, ivory, bones and skins was "driving unprecedented wildlife population declines".