Shoppers on Amazon are unable to pre-order Disney DVDs, in what appears to be the latest contract dispute involving the online giant.

Shoppers are unable to pre-order physical copies of Disney’s latest movie releases including Muppets Most Wanted and Captain America: The Winter Soldier, according to the FT.

Disney joins book publisher Hachette, which has been embroiled in a fierce stand-off over contract negotiations with Amazon for months, which has led the online firm to stop selling its books directly to consumers over the summer.

Amazon published an open letter calling for Hachette authors to put pressure on the publisher to accept lower prices on ebooks. The ecommerce firm said that only by taking “action to reduce sales of their titles in our store” had Hachette “grudgingly began to even acknowledge” Amazon’s argument that high ebook prices were depressing readers’ willingness to buy.

However, more than 900 authors, including Stephen King and John Grisham, retaliated at Amazon by taking out a full-page ad in the New York Times to publish a letter calling on it to stop intentionally slowing book sales during supplier disputes.

The letter read: “Amazon is contradicting its own promise to be the world’s most customer-centric retailer. Many of us have supported Amazon since it was a struggling start-up. This is no way to treat a business partner. Without taking sides on the contractual dispute between Hachette and Amazon, we encourage Amazon in the strongest possible terms to stop harming the livelihood of the authors on whom it has built its business.”

New proposals from Amazon include a charge for publishers for a string of services previously regarded as standard, such as a button to allow customers to pre-order books. The negotiations are expected to become the blueprint for Amazon with the wider publishing industry.