If a claimant knows there is a real possibility that the defendant's act or omission caused the damage of which he complains, this constitutes “knowledge” under s11 and s14 of the Limitation Act 1980. At a date more than three years before they began proceedings, the claimant war veterans reasonably believed that their injuries could be attributed to the nuclear tests conducted by the Ministry of Defence near Christmas Island between 1956 and 1958. A majority of the Supreme Court rejected the claimants’ argument that they did not have the requisite knowledge until the publication in 2007, after these claims were begun, of an expert report providing the first credible scientific evidence that radiation exposure could have caused their illnesses. The claims were accordingly time-barred (Ministry of Defence v AB).