When Tao Rentuo started reading a book he bought from amazon.cn earlier this month - A Global History: From Prehistory to the 21st Century, written by American scholar Leften Stavros Stavrianos - he found it was not an enjoyable reading experience.

"The paper used in the book was of very poor quality, and the printing ink exuded a pungent smell," Tao, a university student in Hefei, capital of East China's Anhui Province, told the Global Times Monday.

Tao suspected he might have bought a pirated book and returned it to Amazon. There have been reports recently that some of Amazon's third-party sellers have been found to be selling counterfeit books, and Tao remembered that the book he bought was from a third-party seller.

"I thought third-party sellers were as reliable as one of Amazon's own units, but from now on I will only buy books from Amazon directly or from other online book retailers," he said.

According to amazon.cn, consumers can apply for a return or replacement if the products they bought from the website have quality problems. But there is not any clause mentioning compensation for consumers if they buy a counterfeit product.

The problem of counterfeit books being sold by its third-party sellers means that Amazon is now facing a credibility crisis with Chinese consumers like Tao.

Piracy complaints

Guangxi Normal University Press found pirated copies of its two bestselling books - Insight, by China Central Television host Chai Jing, and Memoir on Literature, by renowned painter Chen Danqing - were being sold on amazon.cn through the e-commerce company's third-party sellers.

"The two books have been sold by third-party sellers on amazon.cn rather than Amazon itself since late April, and the books were sold with a discount of more than 40 percent off the original price," the publisher said in a statement released on May 15.

To investigate the issue, the publisher bought a total of 35 copies of the two books through these sellers, and found 34 of them were counterfeit copies.

More than 1,000 pirated copies of the two books are sold on amazon.cn through third-party sellers every day, the publisher estimated.

"We have continued filing complaints with Amazon since April, but so far the website has not removed these third-party sellers' product pages," the statement said.

The publisher also claimed that during the process of gathering evidence, some third-party sellers had threatened its employees, as well as making threatening calls to its office.

"Amazon has the responsibility to supervise its third-party sellers and guarantee they sell genuine books," the publisher said. It also decided to suspend supplying copies of the two books to Amazon until the online retailer solves the piracy problem.

Amazon responded on May 16 with a statement saying that it had set up a team to investigate the issue. If the publisher's complaints are true, it said, Amazon will shut down the third-party stores on its platform that sell pirated books.

"We have a strict review system for the qualifications of third-party sellers. Choosing the default seller of a certain product is not manipulated by any Amazon staff members, but decided by the computer system based on a series of factors including the price and customer satisfaction," the statement said.

Starting from Monday, consumers were again able to buy the two books directly from amazon.cn rather than a third-party seller.

"We have restored supplies to Amazon after it closed the third-party stores that were selling pirated books," Sun Ruicen, head of the marketing department at Guangxi Normal University Press, told the Global Times Monday.

Sun said the publisher would not ask for compensation from Amazon or the third-party sellers, as it is difficult to calculate the actual losses it suffered.

"After all, Amazon is still an important business partner for us, and it has promised to strengthen the supervision of third-party sellers," he said.

Others also angry

The Guangxi-based publisher's complaints were echoed by some other publishing companies, who claim they are also victims of pirated books being sold on Amazon.

"Among China's three major online book retailers (the other two are dangdang.com and jd.com), pirated books can only be found on Amazon. Sales of pirated books have led to large losses for Chinese publishers, but Amazon always ignores publishers' complaints," Shen Haobo, president of Beijing-based Motie Publishing Co, said on his Sina Weibo account on May 15.

"We will join in to defend our rights," he said.

This is not the first time that Amazon's third-party sellers have attracted controversy.

The Oriental Morning Post, a Shanghai-based daily, reported on April 11 that many bestselling books were being sold through Amazon's third-party sellers with discounts of as much as 80 percent off the original price, raising publishers' suspicions that they are counterfeit copies.

The publishers said that the low-price books had greatly affected sales of the genuine copies, the report said.

Strict supervision needed

Amazon opened its e-commerce platform to third-party sellers in China in July 2011, allowing small merchants to use its network to sell books and other consumer products.

Unlike other e-commerce companies that charge entry fees or require deposits from third-party sellers, Amazon does not charge any entry fees or annual fees, but collects 4-15 percent of the sales revenue from each item sold by these third-party traders as commission.

Although dangdang.com and jd.com have also opened their platforms to third-party sellers, they both still run their own bookselling businesses.

"Book piracy is rampant in China. That's why local online retailers are cautious about opening the sector to third-party sellers, while Amazon's move is more in accordance with its global strategy," Lu Zhenwang, CEO of Shanghai Wanqing Commerce Consulting, told the Global Times Monday.

Lu said Amazon's strategy could help it quickly expand product lines in China, but also noted that such a strategy has brought side effects, such as direct business competition with its third-party sellers and sales of pirated and counterfeit products on its platform.

Lawyers said Amazon should take a more active role in supervising and inspecting its third-party sellers.

"As the owner and manager of a virtual marketplace, Amazon should assume joint liability for piracy conducted by its third-party sellers," Zhao Zhanling, a lawyer at Beijing Huicheng Law Firm, told the Global Times Monday.

"It is difficult for Amazon to inspect every book sold by its third-party sellers, but the company should strengthen the inspection of the qualifications of third-party sellers and be more active when receiving complaints from publishers or customers," he said.