(Western Journal) Amid increasingly direct attacks by President Donald Trump on Amazon, one author claims an advertisement for his pro-Trump book was blocked by the online retail giant.

As Newsmax reported, Dr. Jerome Corsi attempted to promote “Killing the Deep State: The Fight to Save President Trump” on Amazon through its distributor, Humanix Books. The book has already reached the retailer’s bestsellers list.

Humanix reportedly received a notification from Amazon that the “political content” of the ad violated the site’s policies.