Bolivian officials have accused three miners, including the president of a mining federation, of killing the country's deputy interior minister.
Forty other miners have been detained in the case.
Rodolfo Illanes was kidnapped and beaten to death Thursday by striking miners after he went to Panduro, some 130 kilometers from the capital, La Paz, to mediate in a conflict over mining laws.
An autopsy found that Illanes died of trauma to the brain and thorax.
Protest leader Carlos Mamani was charged Saturday with murder, aggravated robbery, possession of firearms, criminal organization and attacking state officials. A hearing is expected in the coming days.
Bolivian President Evo Morales called the minister's death a "conspiracy" against his governments based on efforts to overthrow him.
During a news conference, he said protests were carried out with backing from the right-wing opposition.
"Now we are getting information and finding documents that say this is to take down the government," he said.
Opposition leaders, however, denied involvement in the minister's murder.
Former president Jorge Quiroga asked Morales "in this sad hour not to weave false conspiracy theories."
Miners were demanding changes in laws, and on Tuesday protests turned violent after they blocked a highway and clashed with police. At least two miners died in the clashes. Miners later agreed to begin negotiations with the government Friday.
Protesters want mining concessions and the right to work for private or foreign companies, and greater union representation.
After the news of Illanes' death, government officials ceased talks with miners and asked for the maximum 30-year sentence for those found guilty in the case.
Illanes' funeral is scheduled to take place Sunday in La Paz.
Some material for this report came from AP and Reuters.
