In Glenn & Anor v Watson & Ors [2016] EWHC 3259 the English High Court considered whether the rules relating to the waiver of privileged information also apply to the waiver of confidential information.

The case concerned an application by Sir Owen Glenn and Kea Investments (a company wholly owned by Sir Owen, but which was owned by Corona Trust at the relevant time) for relief against a transaction that had allegedly been entered into by way of fraudulent misrepresentation.  The defendants sought to question a prospective witness, Mr Miller, about certain matters.  Mr Miller had a significant role, as protector of the Corona Trust, employee, close friend and advisor of Sir Owen for roughly 30 years, and thus a large amount of the evidence he was to give was confidential.  The defendants alleged that the claimants had waived confidentiality in certain matters by referencing those matters in their pleadings.  Conversely, the claimants maintained their right to confidentiality had not been waived. 

It is common practice that pleading a privileged document amounts to an express waiver of privilege, and when doing so the claimant must elect to either to abandon their reliance on the document or to accept that the claimant has waived privilege.  However, the Court noted that it is a separate issue as to whether these same principles apply to waiver of confidentiality in non-privileged communications.  Justice Nugee considered that although confidential matters had been referred to in disclosed documents, and had thereby come into the possession of the other side, this did not mean that the potential witness, who owed a duty of confidentiality, was now free to discuss such matters with anyone else before trial.  Mr Miller's duty of confidentiality remained, which prevented Mr Miller from discussing the relevant topics with the defendants.

See the Court's decision here.