Homicide detectives are travelling to a remote outback mine site following the suspicious death of a man.
Police were called to Pilbara Mineral's Pilgangoora lithium-tantalum mine, about 130 kilometres south of Port Hedland early on Monday morning.
Acting Assistant Commissioner of Western Australian Police Greg Knott said that on arrival at the site, they confirmed the death of a man in his 40s.
"The man's death is being treated as suspicious," Commissioner Knott said.
A 30-year-old man is currently in custody and assisting with the investigation, police said.
Earlier, Pilbara Minerals had asked the Australian Stock Exchange to immediately halt trading of its shares following "an incident" at one of its sites.
Pilbara Minerals managing director Ken Brinsden said he was left aghast by the incident.
"I am extremely shocked and saddened by what has occurred today," he said in a statement.
"At this difficult time, our focus is on ensuring that our people are cared for and supported while we continue to support the police investigation that is currently underway.
"On behalf of Pilbara Minerals, I would like to express our sincere condolences to the affected people and their families."
Pilbara Minerals said the incident, which was "unrelated to mining operations", occurred between personnel at the project.
Operations have been temporarily suspended to facilitate the investigation, the company statement said.
