As eagle-eyed knockoff artists are already no doubt transmitting Internet images from the runways to factories in China, there is a new sector being targeted for counterfeits: fine jewelry.

From Tiffany to Gucci, Van Cleef & Arpels to David Yurman, counterfeiting is becoming a plague for brands in the sector.

Long a thorn in the side of apparel and accessories companies, copycat products — produced mainly in China — are now flooding the market in the fine jewelry arena as the industry becomes more brand-driven by way of high-profile marketing campaigns. It's a problem that has no simple solution except vigilance and the courts. Brands have become much more aggressive in suing the distributors and retailers of counterfeit products, since jewelry design, unlike apparel, is protected by copyright law. But it can be an expensive process chasing down mom-and-pop retailers or e-tailers, and even more costly when giant firms like eBay are taken on, as in a pending case involving Tiffany.

Last week, Cartier, Cartier International NV, Cartier Creation Studio, Van Cleef & Arpels SA, Van Cleef & Arpels Inc., Van Cleef & Arpels Distribution Inc., Gucci America Inc. and Bulgari SpA as plaintiffs, filed suit in Manhattan federal court against Elena Castaneda, who does business as Overstockjeweler.com. Castaneda could not be reached for comment.In court documents, the jewelry brands allege Overstockjeweler.com sells jewelry and watches that it claims are "inspired by," "copies of," "replicas of" and "knockoffs of" a laundry list of jewelry designers, including the defendants in the case, as well as Chanel, Hermès and David Yurman.

The lawsuit was filed for infringements that included trademarks of Cartier, Van Cleef, Gucci and Bulgari, as well as Van Cleef's Alhambra design and Gucci's horse-bit pattern.

In all, the suit includes 45 counts of trademark infringement, false designation of origin, false advertising, trademark dilution, copyright infringement, design patent infringement and trade dress infringement.

The defendants asked the court for an injunction, damages and trial costs. They also asked the court to order Overstockjeweler.com to recall all the allegedly infringing items, as well as advertising and promotional material.

This is the second lawsuit filed against Overstockjeweler.com this year. In February, David Yurman filed suit in Manhattan federal court in a case that is pending.