Troubled Dutch retailer Royal Ahold has said that its investigation into accounting irregularities at its US Foodservice unit is continuing to probe the possible involvement by US Foodservice personnel other than the two individuals identified so far. This latest statement from the beleaguered retailer follows an announcement on Thursday that its probe was "substantially complete" and that two executives, who have since been fired, were responsible for the US$880m overstatement of earnings at its US food distribution subsidiary.