An activist group has claimed to have scraped millions of tracks from Spotify and is preparing to release them online.

Observers said the apparent leak could boost AI companies looking for material to develop their technology.

A group called Anna’s Archive said it had scraped 86m music files from Spotify and 256m rows of metadata such as artist and album names. Spotify, which hosts more than 100m tracks, confirmed that the leak did not represent its entire inventory.

The Stockholm-based company, which has more than 700 million users worldwide, said it had “identified and disabled the nefarious user accounts that engaged in unlawful scraping”.

“An investigation into unauthorised access identified that a third party scraped public metadata and used illicit tactics to circumvent DRM [digital rights management] to access some of the platform’s audio files,” said Spotify.

Spotify does not believe the music taken by Anna’s Archive has been released yet. Anna’s Archive, which is known for providing links to pirated books, said in a blog it wanted to create a “‘preservation archive’ for music”.

The group claimed the audio files represented 99.6% of all music listened to by Spotify users and would be shared via “torrents”, a means of sharing large digital files online.

“Of course Spotify doesn’t have all the music in the world, but it’s a great start,” said Anna’s Archive, which describes its mission as “preserving humanity’s knowledge and culture”.

“With your help, humanity’s musical heritage will be forever protected from destruction by natural disasters, wars, budget cuts and other catastrophes,” said the group.