Crocodylus siamensis was reduced across mainland Southeast Asia by hunting and wetland conversion, to the point that it was widely presumed extinct in the wild in the 1990s. Surveys in the Cardamom Mountains of Cambodia from 2000 onward relocated small populations, and further remnants are known in Laos, Vietnam and Indonesian Borneo. Wild adults are generally estimated in the hundreds.
Meanwhile the species is farmed on a very large scale for skins and meat, with stock numbering in the hundreds of thousands. That abundance does not translate into a conservation reserve. Farms have deliberately crossed Siamese crocodiles with saltwater crocodiles, and sometimes Cuban crocodiles, to improve growth and hide quality, so much farmed stock is of mixed ancestry.
Genetic screening is therefore a prerequisite for any release programme, and reintroduction in Cambodia has depended on identifying pure animals. How much of the farmed population is genetically pure is not accurately known.