An advertisement for online shopping site Taobao.com of Alibaba Group is seen at a metro station in Shanghai, Nov 12, 2014. [Photo/IC]

Sellers of luxurious items on China's biggest online marketplace must prove product authenticity or face being shut down starting May 20, Labor Daily reported.

Alibaba Group Holding's platfom Taobao.com has been frequently criticized for being a hotbed of fake branded products, despite moves to crack down on unscrupulous sellers.

Sources said traders must provide proof their luxury products are authentic and genuine, otherwise these products would be removed or the store closed.

Details of sellers who seriously violate rules will be passed on to commercial regulators or police bureaus for further investigation.

Proof required shall include invoices, receipts or letters of authorization, which will be examined and verified in three to five working days by Taobao before the products are allowed online.

Zhou Ting, director of the Fortune Character Institute, which studies consumption habits of the wealthy, said a great number of non-official sellers of international luxury brands are expected to collapse in 2016 as e-commerce sites toughen their stance on the sale of fake products.

According to the institute, counterfeit luxury products in China outnumber genuine items six to one.