A top policymaker at the US Securities and Exchange Commission on Thursday night sought to defuse an outcry in the UK over comments in which he was reported as having described the London Stock Exchange’s junior Aim market as “a casino”.

Roel Campos, one of five commissioners at the US market regulator, sparked a furious response from the LSE after a Dow Jones newswire report in which he said that 30 per cent of companies listing on Aim were “gone in a year”.