Bolivian deputy Interior Minister Rodolfo Illanes, 56, was killed on Thursday after being taken hostage by workers who had blocked a major highway in Panduro, around 160 km (100 miles) from capital city La Paz. Officials said he died of blows to the head.
According to AP ,the workers were demanding more mining concessions with less stringent environmental rules.
Illanes had traveled to Panduro to negotiate with the miners. His body was found in the early morning by the side of the highway that connects La Paz with the city of Oruro, wrapped in a blanket, said Edwin Blanco, the prosecutor in charge of the investigation.
"The cause of death was basically bleeding in the brain. Ribs were also broken," Blanco told reporters.
Morales said the protests and Illanes' death looked to be part of a "political conspiracy rather than a legitimate social claim" made by the miners.