Amazon has reportedly pulled books relating to autism cures and anti-vaccination misinformation.

As reported by NBC News, the titles Healing the Symptoms Known as Autismand Fight Autism and Winare no longer available on its marketplace.

Amazon confirmed to Mashable the books are no longer available.

Accessing either of those titles turns a "page not found" on Amazon's website, but it's unclear if it's part of a crackdown on books which promote health misinformation. Last week, Amazon pulled anti-vaccination documentaries from Prime Video.

The removal of these books followed a Wiredreport which highlighted how the site is rife with books promoting scientifically unproven and potentially dangerous treatments for autism.

On the listing for Healing the Symptoms Known As Autism, author Kerri Rivera proclaims to be the "foremost expert" on using chlorine dioxide for spectrum disorders.

The Autism Research Institute has warned against the use of chlorine dioxide a.k.a. Miracle Mineral Solution, which shares properties with bleach and has damaging side effects.

In Fight Autism and Win, the authors instruct parents on chelation, which is usually a treatment for acute metal poisoning, like mercury. As noted by the Mayo Clinic, chelation therapy for autism is unproven, and can cause dangerous side effects like deadly kidney damage.

In case you haven't noticed, Amazon's removal is part of a spate of tech giants taking stronger action against health misinformation.

Amid public pressure, Facebook last week decided to make anti-vaccination content harder to find, while YouTube pulled ads from videos which promoted these theories. In February, Pinterest opted to block searches on vaccination entirely.

UPDATE: March 14, 2019, 9:56 a.m. AEDT Amazon confirmed to Mashable that the books had been taken down.