Thailand is investigating the source of excessive cadmium in durian exported to China, with initial tests indicating the problem may lie in durian not originally from Thailand. Preliminary tests have not exceeded China's upper limit, but the source of the contamination remains uncertain, with speculation pointing to a third country. Despite the investigation, China has not banned Thai durian imports, but the country is taking steps to prevent illegal durian imports from neighboring countries that could affect quality and price in the Thai market.