Non-executive bank directors, who often don't have a banking background, will be subjected to new fitness and probity interviews alongside executives and senior management under new practices introduced by the chief executive of the Financial Regulator Matthew Elderfield.

The new initiative involves regulatory officials scrutinising the directors' grasp of risk, audit and compliance functions at board level.

The move represents a strong shift away from the older practice whereby executives and managers submitted written evidence of their fitness to hold senior positions at the banks.

Now the non-executives will have to prove they are up to speed.

In another departure, it has emerged that regulatory staff are conducting exit interviews with departing bank executives to build up a knowledge base of historical risk management practices in the sector.