An open letter urging Spotify to crack down on COVID-19 misinformation has gained the signatures of more than a thousand doctors, scientists and health professionals spurred by growing concerns over anti-vaccine rhetoric on the audio app's hit podcast, The Joe Rogan Experience.

The medical and scientific experts slammed Rogan's track record of airing false claims about the coronavirus pandemic, vaccines and unproven treatments, calling it "a sociological issue of devastating proportions." Spotify, they say, has enabled him.

While audio apps so far have escaped the scrutiny that has befallen social media platforms such as Facebook and Twitter, the pressure on Spotify illustrates how podcasts have emerged as an influential source of misinformation.

In a December episode of his podcast, Rogan interviewed Dr. Robert Malone, a scientist who worked on early research into the mRNA technology behind top COVID-19 vaccines, but who is now critical of the mRNA vaccines.