Londoners have been told to not scan QR codes on the growing number of stickers advertising illicit cannabis websites.

Police are wary of the growing number of ads springing up on lamp posts, bus stops and in toilets around the capital which advertise the drug and its delivery.

Inspector Kerry Goodwin, of City of London Police, said that the ads had been found in Soho and around the Leicester Square area, reports My London.

"Investigations are on-going and we’re working with the City of London Corporation to get the stickers removed as soon as we become aware of them,” he said.

“We'd urge members of the public to alert police if they see any of these stickers and to not scan the QR code."

Scanning the codes is said to send the user onto a website where it appears that cannabis can be bought and delivered.

The sites are also said to advertise CBD and other associated products, such as oils and edibles, with a number of made-up reviews attached to give the essence of authenticity.

A spokesperson for the Met said: "We do not believe cannabis, in any form, is benign."