Governor-General Michaëlle Jean condemned the killing of an activist opposed to a Canadian mine during the last day of a state visit to Mexico while protesters chanted "Canada, get out."
About 50 supporters of Mariano Abarca Roblero were kept about 200 metres from a Mayan women's collective where Ms. Jean visited the colonial town of San Cristobal de Las Casas, about five hours from the mine's location.
"We find it deplorable, inexcusable," Ms. Jean said in a statement Wednesday.
"We will be following this situation closely with the firm hope and conviction that justice will be served."
Mr. Abarca Roblero was gunned down in front of his home in southern Chiapas last month. The community leader had been campaigning against a barite mine operated by a subsidiary of Calgary-based Blackfire Exploration. Three men arrested in Mr. Abarca Roblero's death have ties to Blackfire, either as current or former employees.
State authorities, citing environmental concerns, temporarily shut down the mine this week.
In Canada, Blackfire president Brent Willis said the Mexico mine was run in an environmentally responsible way and the company was in no way connected to the killing.
Mr. Willis said the mine was shut down by state authorities because the company was not properly removing dust from the roads, the company did not obtain proper permits for both a road and CO2 emissions from new mining equipment.
He said the company is working on getting those problems fixed and expected the mine to reopen by Monday.
He denied activists' claims that the mine was harming the environment in any way, saying Mexico has very strict laws that his company has followed to the letter.
Rather than open-pit mines and heavy chemicals used by some companies, Blackfire mines the barite with excavators along the surface of the ground, he said.
"We're running our company ethically and to Canadian standards and we're following all the environmental guidelines," he said. "We're not involved in any type of pollution."
Of the three men arrested in Mr. Abarca Roblero's death, Mr. Willis confirmed one is a former employee, one worked as a contractor doing dust control on the roads and one is currently employed as a supervisor at the mine.
He denied that any of the men had ever acted as security or strongmen for the company and said Blackfire hasn't even been contacted by local authorities about Mr. Abarca Roblero's death, which he called a tragedy.
"The authorities won't talk to us in regards to the investigation," he said. "They're investigating a crime and they're moving forward to find a resolution to this thing."
Mr. Willis said Blackfire has tried to work with local members of the community, many of whom appreciate the company and the employment and local business it brings.
The company invited protesters, including Mr. Abarca Roblero, to come to the site to see environmental safeguards in place, but none would come, he said.
The company policy was to let local Mexican authorities deal with any problems that arose with protesters and employees would have known that, he said.
"Our employees do not get involved with protesters."
The company is now considering hiring security to make sure its employees are safe, he said.
"We want everybody to feel safe, we want everybody to be safe, both employees and people in the community."
Family and supporters of Mr. Abarca Roblero had requested a meeting with the Governor-General, but Minister of State of Foreign Affairs Peter Kent, who was also on the state visit, said it was impossible to schedule.
"The program has been set up and pretty finely engineered over the past several months with regards to the Governor-General," Mr. Kent said. "I think that the time schedule simply being what it was, it didn't work out."
Mr. Kent said Canada is proud of the more than 2,000 Canadian companies currently operating in Mexico.
"A couple of dozen are working in the resource area, specifically in the operational mining area," he said. "In many cases our companies are held up and recognized as virtual models of corporate social responsibility."