The new ebook lending community site Lendle, set up last month to take advantage of Amazon's free Kindle ebook loan facility, has gone off-line after having its API access revoked by Amazon. The site's homepage now warns users the service is "unavailable indefinitely".

Lendle co-founder Jeff Croft, who launched the site six weeks ago, expressed "pure surprise" at the development, saying in an online statement:

"The letter we received from Amazon states that the reason our API and Amazon Associates accounts have been revoked is that Lendle does not 'serve the principal purpose of driving sales of products and services on the Amazon site'. We take issue with this, as Lendle was built from the ground up to ensure that it would be beneficial to authors, publishers and Amazon."

Lendle, like other ebook lending sites, makes it possible for Kindle ebook readers in the US to lend out their ebooks to another member of the site – on a single occasion and for a limited time period of 14 days – and be permitted to borrow someone else's ebook for free in exchange.

Some authors have expressed concern that the sites open up an ebook free-for-all. Crime writer David Hewson this month cited such loan sites as one of the factors, alongside piracy on torrent sites, that are currently "chipping away" at authors' slender incomes.

Croft speculated that "skittish" publishers anxious about the site's effect on sales might have put pressure on Amazon, but admitted that "really, we don't know". He maintained the site does not discourage book buying, saying: "Our site requires that you be willing to lend books before you can borrow them. Our philosophy is: you can't borrow if you don't lend, and you can't lend if you don't buy. The entire system we built is centered around the idea of encouraging people to buy books." The site had engaged with a "passionate, loyal and vocal community many, many thousands of book-lovers strong," he added.

Lendle members voiced anger at Amazon on Twitter today, with this comment from @CleaveLands a typical one. "Good job @amazon," he complained. "Way to kill @lendleapp when they were driving sales of ebooks for your site."

On Twitter, @lendleapp said the owners of other community lending sites had indicated that they too had had API addresses revoked by Amazon. "Lendle has not been singled out," the site tweeted. However, a second ebook loan site, Book Lending, said it was carrying on with "business as usual" today.

Amazon has not responded to requests for comment.