Tesco chairman Sir Richard Broadbent has quit as an inquiry into its accounting reveals a £263m profit overstatement, resulting in a 92% fall in first-half profits.

The supermarket chain said an internal investigation by Deloitte into its procedures had found historic failures in its UK food business.

It had previously suggested the error was a one-off.

Eight senior executives had been suspended pending the outcome of the inquiry, which examined how Tesco logged suppliers' rebates and if they were reported in the correct accounting period. 

The findings raise questions about the tenure of former chief executive Philip Clarke, who stepped down in the summer before the accounting issues were made public.

Tesco said his pay-off - and that of former finance chief Laurie McIlwee - was being delayed until such time as inquiries were complete.