Police in California have closed the case on the mysterious disappearance of Lupita Nyong'o's Oscars dress after the designers decided against pressing charges.

The pearl-covered Calvin Klein frock worn by the 12 Years A Slave star to the recent Academy Awards ceremony disappeared from her room at The London West Hollywood hotel last month (Feb15), and a massive police hunt was launched to recover the garment.

Nyong'o's gown, which was estimated to be worth around $150,000, later turned up in a hotel restroom, and authorities believe the person who took it dumped it after discovering it was worthless on the black market.

A spokesperson for the West Hollywood Sheriff's Department has now confirmed the investigation is over because bosses at Calvin Klein have decided against pursuing a prosecution, telling New York Post column Page Six, "(The) manufacturers have taken possession of the dress and are non-desirous of prosecution. The case has been closed."