1. The deliberate concealment of a material fact by a proposer is a fraudulent breach of the utmost good faith. 2. Limitation Act 1980, s.2, defines the term as ‘the deliberate commission of a breach of duty in circumstances in which it is unlikely to be discovered for some time. The six-year limitation period runs from time of discovery of deliberate concealment with no long-stop provision. Professional negligence errors could go undiscovered for years, but the House of Lords rejected the view that an act of negligence could amount to deliberate concealment (Cave v. Robinson Jarvis & Rolf (2002)). A contrary decision would have meant open-ended liability for negligent professionals.