An undercover investigation into poaching and illegal sales of New York's native turtles, snakes and salamanders has led to charges against 25 people, state environmental officials said Thursday.

More than 2,400 animals, including different species of protected turtles and venomous snakes, were documented in illegal sales or poaching during the two-year operation, officials said.

Investigators posed as vendors at herpetological shows in New York and Pennsylvania, spent hundreds of hours with poachers and trolled Internet sales sites and chat rooms during the operation, authorities said.

In one instance, agents found dozens of endangered Massasauga rattlesnakes hidden in the door panels of a minivan and smuggled from Canada. They had been exchanged for timber rattlesnakes, a threatened species in New York. Canadian agencies brought charges against a man in that case, officials said.

Those charged include 18 people in New York state, six in Pennsylvania, and one in Canada. Charges include buying or selling protected animals and unlawfully possessing or taking protected wildlife.

The investigation also prompted the U.S. Fish and Wildlife Service to pursue federal charges against a Maryland meat processor for buying hundreds of illegally trapped New York snapping turtles, and against a Louisiana turtle farm operator for buying thousands of New York snapping turtle hatchlings for export to China, officials said.

The companies have not been formally charged.

Many of the animals will be returned to their native habitats.

New York has one of the strictest laws in the U.S. protecting its reptiles and amphibians from being bought and sold. A law enacted in 2006 bans all commercial trade in the state's native reptiles and amphibians.