PwC’s US and UK operations have confirmed that they will cooperate with an international investigation into the tax scandal engulfing the firm in Australia. This is the clearest signal yet that the scandal has become a global problem for the consulting group. The investigations come after the firm appointed former NBN co-chairman Ziggy Switkowski to lead an independent review of PwC’s troubled Australian operations, with the power to recommend the firing of people involved, as former chief executive Tom Seymour announced his resignation from the firm. Seymour led PwC’s tax operation when confidential information was widely shared within the firm and marketed to multinational clients following a confidentiality breach by PwC partner Peter Collins. A document released by the Senate inquiry showed Collins repeatedly leaked confidential information with senior PwC staff about government plans to combat tax avoidance over three years, for PwC’s benefit. The information spearheaded a push for new business, including the Silicon Valley-based US tech giants and a group dubbed the “dirty 34”. Three of the largest global corporations – Apple, Google and Microsoft – are believed to be among the targets. Partners from both of these operations will be exposed if a senate estimate hearing, and a separate senate inquiry, succeed in obtaining the names of the partners implicated in the scandal and the global companies they targeted.