Three workers of Canadian Mining firm Blackfire Exploration have been arrested by Mexican authorities in connection with the alleged murder on 27 November of an anti-mining activist.
Activist Mariano Abarca was demanding that the Blackfire barite mine in Chicomuselo, which used to produce drilling fluids, be closed, according to Dow Jones.
Abarca was a member of Mexican group REMA which led protests in Chicomuselo against the Blackfire mine. He had been arrested earlier this year for his involvement in protests against the mine.
It is alleged that a weekend driver for Blackfire, Jorge Carlos Sepulveda Calvo, shot Abarca, Chiapas state prosecutors said in a release.
It is not yet known the role the other two alleged offenders had in the matter.
Blackfire was also asked to close its barite mine in Mexico this week by the government, with a spokeswoman alleging it was polluting and emitting toxins.
The mine had been operating since November last year and according to reports by Bloomberg, Blackfire was not properly told of the reason for the demand to close.