Over 50% of WestLB's provisions against fraud losses were taken against its loans to RBG Resources, the collapsed London metals dealer under investigation by the UK's Serious Fraud Office (SFO).

The RBG disaster, combined with unspecified losses at Box Clever, the TV rentals business, is a further blow to WestLB and Robin Saunders, the German bank's head of principal finance, who is associated with headline-making deals for entrepreneurs like Philip Green at BhS and Bernie Ecclestone at Formula One.