A lawsuit filed and then withdrawn last month against Alibaba Group Holding Ltd. by several of the world's leading luxury brands provides extensive details about the issue of allegedly counterfeit goods on the Chinese Internet company's shopping platforms.

The 147-page complaint, filed July 9 in the U.S. by Gucci, Yves Saint Laurent and other brands under Kering SA, alleged that Alibaba's shopping, marketing and payment platforms "knowingly make it possible for an army of counterfeiters to sell their illegal wares throughout...