This case involved an HMRC official giving an 'off the record' briefing about tax avoidance schemes. In so doing, they disclosed details of a particular taxpayer's affairs.
The court considered confidentiality under the Commissioners for Revenue and Customs Act 2005, as well as the general common law confidentiality rules.
The Supreme Court held that where personal or confidential information was obtained in furtherance of a public duty it should not be passed on to third parties. Importantly, this applies even where confidential information is passed on in confidence, or on an 'off-the-record' basis.
The case: R (on the application of Ingenious Media Holdings plc and another) v Commissioners for Her Majesty's Revenue and Customs  UKSC 54
Organisations receiving information in confidence should ensure it is not passed on to third parties without authorisation, even if passed on 'off-the-record, or they risk facing a breach of confidentiality claim