Well, the dress has been found ... to be a fake!
The thief who took the gown says he took the dress from Lupita's room at The London after finding the door ajar.
[Image via WENN.]
The actress showed us a different side of glam in a black and white print Giambattista Valli dress featuring long sleeves and a voluminous, cape-like back.
It was definitely a departure from all the sparkly gowns, but we love it when actresses take risks, and Diane is a risk-taker extraordinaire!
[Image via Brian To/WENN.]