AS many as six suburban pokies venues owned by billionaire Bruce Mathieson are under investigation by federal and state authorities for allowing Vietnamese syndicates to launder millions of dollars of suspected drug money through their gaming machines. The Australian Leisure and Hospitality Group, jointly owned by the Mathieson family and Woolworths, confirmed that federal financial regulator Austrac and the Victorian Commission for Gambling and Liquor Regulation were examining evidence of large-scale cheque-buying at its venues, a practice that allows criminals to launder money and problem gamblers to plough jackpots back into machines.