Brands promoting their products online are quietly deploying AI-generated influencers on social media, an investigation has found, prompting calls for greater transparency.

The findings suggest companies are increasingly turning to AI-generated content that purports to show genuine customer experiences while giving no obvious indication that the people featured are not real.

The Guardian has also found that some content creators making AI influencer content are being asked to sign non-disclosure agreements so they cannot talk about their work.

There are no specific rules requiring brands to tell consumers when advertising content has been created using AI. In the EU, new rules under the Artificial Intelligence Act will begin applying in August, requiring AI-generated or manipulated content such as deepfake images, audio and video to be clearly labelled. The legislation will not apply in the UK.

The consumer group Which? said that customers should be clearly informed when promotional content features AI-generated influencers rather than real people.

One example of a business appearing to use this content on Instagram includes a photo app called Once, which allows people’s phones to create disposable camera-style photographs for events. According to analysis by Reality Defenders, a cybersecurity company specialising in deepfake detection, the brand has likely used AI-generated influencers in its promotion.

Several videos on Instagram show a bride crying and saying she was pleased to have used the Once app at her wedding. In one she says: “Everyone expected a no-phone wedding, so I gave them cameras instead.” The post was captioned, “The app I used is called @oncefilmapp.”

When asked about this, Once did not respond to a request for a comment.

In another video a woman who appears to be AI generated says in a caption on the screen: “I could kiss the interior designer who showed me this.” She then goes on to show herself using the Maket app, which uses AI to design and plan housing projects.

Maket said: “AI-generated influencers have been one of several ways for us to test creative concepts and marketing hooks at a small scale before investing in broader campaigns. This is not a core part of our marketing strategy, but rather an experiment to better understand what resonates with audiences across channels, including influencer, social media and email campaigns.”

A fashion brand called Ashle, a Dubai-based business, posted a photograph appearing to show a woman wearing its clothes at a restaurant. The woman appears to have an extra finger. After being approached by the Guardian to ask about the use of AI influencers, the brand deleted photographs from its social media page.

A spokesperson for Ashle said: “To clarify, all Ashle pieces are real garments that are handmade to order. We are not selling AI-generated products. Some early marketing imagery utilised AI during our initial launch phase to showcase designs.

“The images that have been removed were taken down because those particular designs are no longer part of the collection, not because they were AI-generated.”