BBC, 05/25/2011
Joao Claudio Ribeiro da Silva had long been an environmental campaigner
A prominent Brazilian conservationist and his wife have been killed in the Amazon region, police have said.
They said Joao Claudio Ribeiro da Silva and Maria do Espirito Santo were ambushed in Para state, near the city of Maraba.
The environmentalist had repeatedly warned of death threats against him by loggers and cattle ranchers.
