Bosses at 20th Century Fox are investigating the theft of a script for an upcoming episode of creepy Tv drama American Horror Story.

One page detailing a key scene revealing the mystery of a plotline from the show's previously-aired second season was reportedly taken from the set during a shoot in New Orleans, Louisiana earlier this month (Nov14).

It contains the answer to a storyline that kept viewers hooked during the show's 'Asylum' season in 2012.

A representative for 20th Century Fox Tv tells Tmz.com, "The theft and unauthorised distribution of our scripts is a very serious matter and we will take all appropriate steps necessary to vigorously protect our intellectual property."