A Baldivis fly-in, fly-out worker ended up in the State trauma ward one day before the site introduced a four-drink limit in response to a series of sex assaults. The 52-year-old man was allegedly punched at Rio Tinto’s Gudia-Darri mine site near Newman in the State’s north on July 10 about 8.45pm. A police spokeswoman said two men aged in their 40s and 50s became involved in a physical dispute. “During the altercation a man in his 50s was punched, causing him to fall backwards and hit his head on the concrete ground,” she said. “The man received serious head injuries and was airlifted by the Royal Flying Doctor Service to Royal Perth Hospital for treatment.” It is understood the victim had been playing music before the site’s curfew and the accused had told him to turn it off. A Royal Perth Hospital spokeswoman confirmed the victim arrived at the hospital at 5.13am on July 11. She said he was in a stable condition and receiving treatment in a general ward. Rio Tinto introduced serving limits of four mid-strength drinks per day on July 12. The move followed a similar policy introduced by BHP. Police said the investigation was ongoing. A Rio Tinto spokesman said the matter was referred to WA Police and the company was conducting an internal investigation into the incident, which had also been reported to the Department of Mines, Industry Regulation and Safety. “The individuals involved left the site and have been stood down pending the results of the investigation,” he said. A parliamentary inquiry chaired by WA Liberal deputy leader Libby Mettam will examine sex assaults on WA mine sites.