In April 2011 Australia's Fair Work Ombudsman began an investigation into claims that foreign workers were underpaid on two North West Shelf oil rigs operated by Woodside Petroleum. In April 2013, the Federal Court in WA heard allegations that the workers were paid less than $3 an hour to work on the oil rigs. Documents tendered to the court claimed that the four men worked as painters on Woodside rigs on the North West Shelf off northern WA from July 2009 until early 2011.