The Music Publishers Association has asked the US Federal Trade Commission (FTC) to investigate Spotify after it added audiobooks to all of its paid subscription plans. According to the complaint, the recent actions of the service are part of a “scheme to increase profits by deceiving consumers and cheating the music royalty system,” Engadget reports.

In November 2023, Spotify announced that it would include 15 hours of audiobook listening to all of its Premium plans. A few months later, the company introduced a new audiobook-only subscription offering the same number of hours of listening for $10 per month.

The publishers’ organization claims that the recent Spotify price hike is based on the supply of this additional content and that paying customers are automatically charged for a service they did not choose and cannot opt out of without switching to free listening with ads.

And the additional income from the higher cost of Premium subscriptions may not go to composers. According to the FTC’s complaint, Spotify will pay an estimated $150 million less in music royalties during the first year of the new package plans.

The complaint calls the new audiobook plan a “sham” that “exists solely to allow Spotify to claim that audiobook content is a significantly and independently valuable aspect of its ‘bundled’ Premium Plan, as the Audiobook Access Plan costs only $1 less than the Premium Plan with the exact same audiobook content and music.”

At this early stage, it’s hard to say whether the issue will affect Spotify’s planned overhaul of its royalty model. Both artists and publishers regularly criticize the streaming ecosystem in general and Spotify in particular for underpaying musicians.