Art by Anish Kapoor and David Bailey that was sold as NFTs without their consent

Star Wars Stormtrooper helmets by artists including Sir Anish Kapoor and David Bailey were photographed without their consent and sold as non-fungible tokens (NFT), with the images collectively selling for millions of pounds on Monday.

Curator Ben Moore photographed some of the helmets from a project called Art Wars, created by more than 300 artists since 2013, and sold them for cryptocurrency as NFTs on trading platform OpenSea. More than 1,600 Ethereum (£5 million) have been transferred since the collection of 1,138 images went up for sale yesterday.

An NFT attributed to Kapoor was priced at 1,000 Ethereum when it was marketed for resale on the site back on Monday, while another work attributed to Bailey was offered for resale for 120 Ethereum. Both images have since been removed from the site.

About 12 artists are considering legal action against the project, according to legal representatives.

A representative for Bailey said he neither gave permission nor received the proceeds of the sale. They said they would investigate. Kapoor's team declined to comment.

Damien Hirst, whose work was included to promote the collection but not sold as an NFT, did not respond to a request for comment.

The Art Wars NFT page on OpenSea was shut down yesterday. OpenSea said it received a notice of copyright infringement and complied with it.

The dispute highlights the debate surrounding ownership of NFTs. Buyers of NFTs do not own the physical artwork and digital versions are sometimes sold without the permission of the original owners, creating conflicts over intellectual property.

Moore sent an email to artists on Nov. 4 to inform them of the collection, but some artists said the email ended up in their junk folders, their lawyers claimed.

Moore did not dispute the claims that he created the NFTs without the artists' permission. “[Art Wars] regrets that some of the artists were caught off guard and have since requested not to be included – of course we have respected those wishes,” he said.

All artists remaining on the project would “receive royalties in the usual way,” Moore added, saying the NFT project had raised £30,000 for charity.

Meanwhile a photo of Moore shared on Twitter and originally posted to his Instagram Stories early Monday.

Moore said people might assume he was showing off, but it was a "small sign of celebration."

London-based artist Helen Downie, who goes by the name Unskilled Worker, is among those threatening legal action after discovering that two of her helmets were being sold as NFTs via Twitter.

“I was initially tagged in a tweet from a buyer who said he was delighted to own a piece of my work,” she said. “The problem was I had no idea how they bought it.

“If the exploitation of artists’ intellectual property goes unchallenged, this behavior will ruin and corrupt a truly exciting space for artists and collectors alike.”

The photographs of art by unskilled workers were successfully removed from the Opensea platform upon request.

The Design and Artists Copyright Society said minting NFTs without artists' permission has the "potential to destroy how we as a society value creativity." She makes requests for several participating artists.