Nick Leeson, the rogue trader responsible for the collapse of Barings Bank, has lambasted the UK financial regulator for the long delay in deciding what, if any, punishment should be given to the chief executive of Barclays over the mishandling of a 2016 whistleblowing incident.

Barclays boss Jes Staley is being investigated by the FCA over claims he tried to uncover the name of a whistleblower who wrote a letter raising concerns about one of the CEO's former JPMorgan colleagues hired by the UK bank.