A Netflix-style eBook subscription service is being tested by Amazon. Reuters

Amazon is testing a new eBook and audio-book subscription service that offers users unlimited access to over 600,000 titles for a fixed monthly fee.

The Kindle Unlimited service was first noticed by members of a Kindle chat forum but the pages revealing details on Amazon's website were deleted shortly after. The page can however still be viewed as a cached copy.

Titles available through Kindle Unlimited include the hugely popular Harry Potter and Hunger Games series as well as the Lord of the Rings trilogy.

Kindle Unlimited - Netflix for ebooks
Amazon is currently testing Kindle Unlimited, a Netflix for ebooks service which will cost $9.99 a month.

In an Editor's Picks section, more recent titles like Thomas Piketty's Capital in the Twenty-First Century are available, however none of the 'Big Five Publishers' appear to be involved in Kindle Unlimited.

The price of the service is marked as $9.99 (£5.85), with a free 30-day trial, making it a similar offering to Netflix's unlimited television and film streaming service.

A video that appears to be a short promotional film for Kindle Unlimited was picked up by technology news site Gigaom.

"Introducing Kindle Unlimited: The freedom to explore over 600,000 titles and thousands of audiobooks in the palm of your hand," the video states. "Enjoy unlimited reading and unlimited listening on any device."

Authors have already expressed concerns about how they might receive payment if their titles appear on Kindle Unlimited.

"Anyone know how we are going to get paid for these books? Is it just another barrow? I can't imagine it would be, or they'd lose money on the deal," M J Ware, a children's horror author, wrote on a writer's forum.

Amazon has been contacted by IBTimes UK but is yet to confirm when Kindle Unlimited might be available, if at all.