Philip Clarke CEO Tesco

Ex Tesco boss Philip Clarke

Former Tesco boss Philip Clarke has been summoned for an interview by the Serious Fraud Office (SFO) as it steps up its criminal probe into an accounting scandal at Britain’s biggest supermarket.

Clarke, who departed as Tesco chief executive last year, has received an interview request from the SFO, alongside the supermarket's ex-commercial director Kevin Grace.

Former finance chief Carl Rogberg is thought to have been interviewed earlier this summer, while former head of UK operations Chris Bush has also received an interview request, according to Bloomberg.

The news comes in a week where figures have showed the supermarket’s market share has slipped to its lowest level in a decade (28.3 per cent) under new CEO, Dave Lewis.

The SFO launched its investigation last October after Tesco said it had discovered it had overstated its profits for the first half of the year by £263m.

Executives are suspected of inflating profits by booking payments from suppliers they should not have.

The scandal was discovered by Lewis shortly after he took the helm. Nine senior managers have been suspended - of which at least six have been dismissed.

Although there is no suggestion that Clarke knew of the alleged scam, it occurred on his watch.