This isn't the first time the athletic wear company has levied an accusation against a retailer selling supposed Lululemon dupes.

Lululemon is accusing Costco of stealing from its "path-breaking" brand by selling dupes of its sweatshirts, jackets and pants.

Lululemon has filed a lawsuit against Costco that accuses the wholesale club operator of selling lower-priced duplicates of some of its popular athleisure clothing.Lululemon Athletica claims in its lawsuit filed in the U.