Power suppliers could be required to clamp down on electricity theft under new rules proposed by the regulator Ofgem.

Suppliers would have to bring in measures to detect, investigate and prevent cases.

The industry falls victim to up to 25,000 cases of electricity theft every year, costing consumers at least £200 million, or £7 per electricity customer, Ofgem said.

Up to one-third of the volume of electricity stolen each year is used to power cannabis farms.

Now Ofgem wants new rules to be brought in to reduce the amount of theft, with fines for suppliers who do not comply.

Andrew Wright, Ofgem's chief executive, said: "Ofgem wants to make sure consumers are paying no more than they need to for their electricity, and lives are not put at risk. It's critical suppliers do all they can to clamp down on electricity theft."

Energy UK, which represents energy companies, welcomed the proposals.