Skilled Hungarian engineers on 457 visas claim they were employed as labourers and underpaid Promised higher wages: The workers with union spokesman Brian Parker, centre. A group of Hungarian men brought to Australia on temporary visas to work as highly skilled technicians have instead been used as labourers on a western Sydney warehouse. The 20 workers said they were promised Australian rates of pay of about $30 an hour. Instead for the last four months they have been paid about $15 an hour to help build the warehouse, in Eastern Creek. The men were working as riggers building steel structures, forklift drivers and general labourers - and not as the mechanical engineering technicians their 457 visas specified. None of the men have qualifications or experience as mechanical engineering technicians. The underpayment and visa rorting allegations were raised on Saturday. Soon after, it is alleged the Austrian company employing the men requested those who had complained to get on a plane to Hungary. Three returned home, but 17 remain. The Construction Forestry Mining and Energy Union is now representing the men. It argues the case is the latest highlighting the use of controversial 457 visas by unscrupulous employers. The case is being investigated by the Fair Work Ombudsman. A spokesman for Immigration Minister Scott Morrison said the department had started investigating the matter. The workers were brought in by Austrian company Assmont, and their visas approved by a Department of Immigration case officer based in Vienna. Assmont construction manager Alois Aigner said the company was now "checking all of the regulations" but declined to talk further about the conditions the men were brought to Australia on. The majority of the men have little or no English. A Department of Immigration letter to one of the workers, Istvan Erdei, shows he is allowed to work as a mechanical engineering technician - something he is not qualified to work as. He said through an interpreter that the men had been underpaid and treated badly. Mr Erdei said their supervisor in Australia did not speak Hungarian. Only German and only one of us can speak broken German. The warehouse's shell had been built and the internal fitout had been contracted to Schaefer Systems International, which relied on Assmont to supply labour. The warehouse will ultimately be occupied by supermarket chain IGA. The union's national construction division secretary, Dave Noonan, said it was another "blatant rip-off" of 457 visa holders.