Already embattled Huawei came in for criticism from users after advertisements began appearing on the lock-screen of smartphones.

The ads from travel company Booking.com impacted customers who used Huawei’s pre-installed wallpaper carousel and the images could be manually deleted.

TechRadar noted while Huawei had apologised for the inconvenience and removed the adverts from its servers, it offered no explanation for the issue.

Some reports suggested the blame had initially been placed on the Booking.com app, which is preinstalled on some smartphones, though Huawei’s comments suggest this was not the case.

The idea of serving ads to device lock screens is not new, with Amazon having previously offered the feature on its own-brand and partner devices, albeit with a trade-off on the cost of the phones.

With not all Huawei devices being affected and no explanation given for the move, it is certainly possible the branded wallpapers may have been an error. The fact that only one advertiser appears to be involved also suggests it was not intended to be a commercial launch.

However, the problem was widespread: reports stated the ads owners of the P30 Pro; P20 Pro; P20; P20 Lite; and Honor 10 in the UK; Netherlands; Republic of Ireland; South Africa; Norway; and Germany were affected.

If it was an attempt to trial user acceptance of lock-screen ads, then the company received its answer loud and clear.