Spanish workers 'ripped off' at NT mine SPANISH workers are being paid half the wage of Australian workers at a remote Northern Territory mine, a union claims. The Australian Manufacturing Workers Union (AMWU) says the 14 diesel fitters, employed under the 457 visa program, are also working longer hours at the McArthur River mine, about 800km southeast of Darwin. AMWU NT organiser Brian Wilkins says the union was tipped off about the workers at the site, run by McArthur River Mining, about six weeks ago. "These Spanish workers are out there in the middle of nowhere and they're being ripped off," he told AAP. We understand there are skills shortages in this country, but those shortages shouldn't be used to undercut anyone's wages. Mr Wilkins went to the mine to talk to the Spanish workers, but claims the mine's operators kept a close watch over him. "None of the workers were brave enough to approach me," he said. The union then reported it to the Department of Immigration, which has launched an investigation. The mine is one of the world's largest zinc, lead and silver mines and is run by McArthur River Mining, a subsidiary of Xstrata. Comment has been sought from the company, Department of Immigration and the NT Department of Primary Industry and Fisheries.