Inner city areas of the Midlands and north of England, former mining areas and declining coastal resorts were also pinpointed as blackspots by the report.

BBC: Welsh houses are 'crumbling'

De Beers is active in every category of industrial diamond mining: open-pit, underground, large-scale alluvial, coastal and deep sea.

FORBES: Anglo American Receives Final Regulatory Approval for De Beers Acquisition