Brazil has detained a land-grabber thought to be the Amazon's single biggest deforester, the country's environmental protection agency says. The Brazilian Institute of Environment and Renewable Natural Resources says Ezequiel Antonio Castanha, who was detained Saturday in the state of Para, operated a network that illegally seized federal lands, clear-cut them, and sold them to cattle grazers. The agency blames the network for 20% of Amazon deforestation in recent years. The agency's head of environmental protection says the arrest of Castanha, who could be sentenced to up to 46 years in prison, could "contribute significantly to controlling deforestation in the region." (More Brazil stories.)