Legal professional privilege
Confidential communications between a client and the client’s legal adviser can be privileged (and inadmissible in the courtroom) if made for the dominant purpose of submission to the legal adviser for advice (whether connected with litigation or not) or for use in existing or anticipated litigation. The privilege promotes the public interest by preserving the confidentiality of communications between lawyer and client and by encouraging the client to make full and frank disclosure to the legal adviser. In doing so, the privilege outweighs the competing public interest that, in the interests of a fair trial, all relevant material should be available (Esso Australia Resources Ltd v FCT (1999) CLR 49).
Legal professional privilege may be waived where the actions of a party are plainly inconsistent with the maintenance of the confidentiality which the privilege is intended to protect (Expense Reduction Analysts Group P/L v Armstrong Strategic Management and Marketing P/L  HCA 46).