Organised crime groups have been targeting empty shops and pubs in town centres to grow cannabis on an industrial scale, say police bosses.

Over the last year, raids have been carried out in dozens of properties, from an old toy shop in Ayr, Scotland, to a former bank in Welshpool, Powys.

Vacant restaurants, cafes, nightclubs, bingo halls and office buildings have all been used to grow the drug, according to the National Police Chiefs’ Council.

In Newport, south Wales, criminals used several floors of a former department store on the main shopping street to grow more than 3,000 cannabis plants.