IGUALA (Reuters) - Three employees of Canadian miner Goldcorp Inc were found dead, family members said, after they were believed to have been abducted in restive southwestern Mexico.

The corpses were found on Friday in a mass grave in Guerrero state and showed signs of torture, the relatives said. It was the same state where 43 trainee teachers were abducted late last year and apparently massacred, in an incident that sparked President Enrique Pena Nieto’s deepest political crisis.

State authorities declined to comment when asked about the discovery.

The state prosecutor’s office said on March 6 that four employees of Goldcorp, the world’s biggest gold producer by market value, had possibly been kidnapped. Prior to their disappearance, they were believed to be headed home after finishing their shifts at the Los Filos mine.

The fourth employee has since been freed, according to family members.

“The information available to us about this incident is limited, however the disappearance of the employees was unrelated to their role with Goldcorp,” Goldcorp spokeswoman Christine Marks wrote in an e-mail on Sunday.

“The employees were not at the mine conducting Goldcorp business or in Goldcorp-supplied transportation at the time of the incident,” she added.