On the 28th of August 1995, Fox TV in the US released a documentary called 'Alien Autopsy: Fact or Fiction', hosted by Jonathan Frakes (Riker in Star Trek: Next Gen) which purported to show scenes from an explosive 7-minute black-and-white film depicting a secret medical examination or autopsy of a seemingly extraterrestrial being, or alien, by the American military. The doc featured analysis from luminaries such as Oscar-winning special effects make-up artist Stan Winston, cinematographer Allen Daviau, and noted forensic pathologist Cyril Wecht. Fox re-broadcast the program twice, each time to higher and higher ratings, and Time Magazine said the film had sparked a debate "with an intensity not lavished on any home movie since the Zapruder film [the film of Kennedy's assassination]"
The original film was released by London-based business-man Ray Santilli who appeared in the Fox programme. He presented it as an authentic autopsy on the body of an alien recovered from the 1947 crash of a "flying disc" near Roswell, New Mexico. The film footage was allegedly supplied to him by a retired military cameraman who wished to remain anonymous. A film-director hired by Fox to direct some sections of programme was highly suspicious of Santilli and said he reported this to the producers. He later said "It was then made clear to me that if the footage was exposed as a hoax before the show aired, the ratings would suffer." In 2006, Santilli appeared in a Sky TV documentary hosted by Eamonn Holmes saying he had seen the original footage but admitted that the film he released was actually a "reconstruction" containing only, in his words, "a few frames" from an original twenty-two rolls of film (each averaging four minutes in length).
Santilli, and fellow producer Gary Shoefield admitted filming a simulated autopsy on a fabricated alien, based upon what Santilli said he saw in 1992, and then adding in a few frames of the original film that had not degraded. They have not identified which frames are from the alleged original. According to Santilli, a set was constructed in the living room of an empty flat in Camden Town. The 'body' was a dummy, containing sheep brains set in raspberry jam, chicken entrails and knuckle joints. in 2006, a comedy movie of the hoax, called Alien Autopsy, was released starring Ant & Dec as the filmmakers. You can view the autopsy here: https://youtu.be/m9lTaQMvDvs.