The consumer champion Which? found companies appear to be gathering far more data than is needed for products to function. This includes smart TVs that ask for users’ viewing habits and a smart washing machine that requires people’s date of birth.

Rocio Concha, director of policy and advocacy at Which?, said: “Consumers have already paid for smart products, in some cases thousands of pounds, so it is excessive that they have to continue to ‘pay’ with their personal information.”

For smart cameras and doorbells, Which? found Ezviz devices, sold by major high-street retailers including Argos, had by far the most tracking firms active. This included TikTok’s business marketing unit, Pangle, Huawei, as well as Google and Meta.

Every single smart camera and doorbell brand Which? assessed used tracking services from Google, while Blink and Ring also connected to parent company Amazon. Google’s Nest product demands a user’s full name, email, date of birth and gender.