Publisher Bloomsbury has said it was unaware an image it used on the cover of a book by fantasy author Sarah J Maas was generated by artificial intelligence.

The paperback of Maas’s House of Earth and Blood features a drawing of a wolf, which Bloomsbury had credited to Adobe Stock, a service that provides royalty-free images to subscribers.

But the Verge reported that the illustration of the wolf matches one created by a user on Adobe Stock called Aperture Vintage, who has marked the image as AI-generated.

A number of illustrators and fans have criticised the cover for using AI, but Bloomsbury has said it was unaware of the image’s origin.

“Bloomsbury’s in-house design team created the UK paperback cover of House of Earth and Blood, and as part of this process we incorporated an image from a photo library that we were unaware was AI when we licensed it,” said Bloomsbury in a statement. “The final cover was fully designed by our in-house team.”

This is not the first time that a book cover from a major publishing house has used AI. In 2022, sci-fi imprint Tor discovered that a cover it had created had used a licensed image created by AI, but decided to go ahead anyway “due to production constraints”.

And this month Bradford literature festival apologised “for the hurt caused” after artists criticised it for using AI-generated images on promotional material.

Meanwhile, sci-fi publisher Clarkesworld, which publishes science fiction short stories, was forced to close itself to submissions after a deluge of entries generated by AI.

The publishing industry is more broadly grappling with the use and role of AI. It has led to the Society of Authors (SoA) issuing a paper on artificial intelligence, in which it said that while there are “potential benefits of machine learning”, there are risks that “need to be assessed, and safeguards need to be put in place to ensure that the creative industries will continue to thrive”.

The SoA has advised that consent should be sought from creators before their work is used by an AI system, and that developers should be required to publish the data sources they have used to train their AI systems.

The guidance addresses concerns similar to those raised by illustrators and artists who spoke to the Guardian earlier this year about the way in which AI image generators use databases of already existing art and text without the creators’ permission.