Sir Ben Wallace knew that allegations about the killings of Afghan civilians by SAS forces were “broadly accurate” four years before ordering a public inquiry, a hearing was told.

The former defence secretary Ben Wallace was advised by his permanent secretary that a public inquiry into allegations of SAS executions in Afghanistan would be “expensive, unproductive and extremely bad” for the reputation of the British military.

A former Defence Secretary has strenuously denied claims by a political rival that he was told about SAS war crimes in Afghanistan.Giving evidence at the High Court, Ben Wallace fired back at Johnny Mercer who previously suggested he had shown a 'lack of curiosity' about the allegations.