Did Sienna break her contract?

Sienna Miller may have broken a contract with Pepe jeans by wearing another brand. The actress signed an exclusive deal to be the "face and body" of Pepe, but was photographed wearing jeans by LoFli. "Not only did Sienna do a racy photoshoot on a beach in Malibu, she also agreed in writing not to wear rival products. Not surprisingly Pepe now want her to explain what's going on," a source told a British newspaper. However, Pepe released this statement: "Sienna is contracted only to wear Pepe jeans, so we're sure this must be an old photograph."