Disciplinary investigations into professional misconduct allegations almost inevitably involve examination of documents held by the person under investigation. Where such documents attract legal professional privilege, belonging either to the professional's client or to the professional himself, the question arises whether the investigator can demand their production. That question becomes particularly acute where the investigation concerns the professional conduct of a barrister or solicitor, as in the recent New Zealand case, B v. Auckland District Law Society [2003] UKPC 38.