Bangladesh, Jan. 7 -- Deforestation in Brazils Amazon region has long been driven by illegal logging, land grabbing, and weak enforcement. But in the western Brazilian state of Mato Grosso, authorities and environmental groups now warn that the nature of this crime is changing in a dangerous way. What was once largely the work of small-scale loggers and local actors has increasingly become the domain of organized criminal groups with money, logistics, and even armed capacity to operate deep inside protected forests.

Recent data illustrates the scale and urgency of the problem. According to a report by the environmental non-profit Instituto Centro de Vida (ICV), Mato Grosso lost nearly 50,000 hectares of forest to illegal logging in just ...