The most recent files release confirms the US government is seriously concerned about cattle mutilation and who or what is responsible for them.
You can read through the cattle mutilation files here yourself if you wish.
More than 8,000 cattle were snatched by mystery aircraft, mutilated, then dropped from the skies above the US south west in the late 1970s, special agents told their directors.
Terrified farmers in New Mexico, Nebraska and Colorado feared they would be ripped apart by extraterrestrials in flying saucers.
Details of the probe are spelled out in internal memos released by the FBI online.
The cattle killers took sick TROPHIES including tongues, lower lips, sex organs, eyes and ears. In some cases the doomed animal was drained entirely of its BLOOD.
One investigator set out his theory: "These animals are picked up by aircraft, mutilated elsewhere and returned and dropped from aircraft.
"Identical mutilations have been taking place all over the south west. Whoever is responsible is well organised with boundless technology, financing and secrecy."
Files from the New FBi Vault
In January 1979, then US Attorney General Griffin Bell wrote to spooked senator Harrison Schmitt, saying: "The materials sent to me indicate one of the strangest phenomenon in my memory."
Mr Schmitt represented New Mexico - where, from 1976 to 1978 there were numerous mysterious incidents at a ranch in Dulce.
One chilling police report detailed a feared alien sacrifice there: "This 11-month-old bull was dropped by some type of aircraft north of Mr Manuel Gomez's ranch house. The sex organs had been removed with a sharp and precise instrument. The bone had also been removed.
"The bull sustained visible bruises around the brisket seeming to indicate that a strap was used to lift and lower the animal from the aircraft... flesh underneath the hide was pinkish in colour.
"A probable explanation for the pinkish blood is a control type of radiation used to kill the animal... both the liver and the heart were mushy. Both organs had the texture and consistency of peanut butter."
The bull had been seen alive the previous day but during the night a low-flying craft had been heard near where the remains were found. FBI agents were sent to remote farms across rural America to probe the killings.
A police report of another incident at the Dulce farm, dated June 13, 1976, told how an odd craft visited another animal mutilation.
"A suspected aircraft of some type had landed twice, leaving three pod-marks in a triangular shape. The diameter of each pod was 14inches." (if you remember the rendlesham case in the UK airforce base you will recall they also recorded the exact same imprints)
An FBI document dated January, 1979, said: "The Department of Justice advised that their criminal division has been aware of the phenomenon of animals being mutilated in a manner that would indicate such acts were performed by persons as part of a ritual or ceremony."
Kenneth Rommel, who led the FBI's Animal Mutilation Project probe, wrote a bombshell memo on March 5, 1980, on one alien swoop.
It stated: "In July 1978 a UFO was reportedly sighted by a resident of Taos, New Mexico, hovering over a pick-up truck. The following morning powder flakes were reportedly recovered from the truck roof."
Locals told the FBI the flakes came from COW HIDES, he added.
Possible theories for the mutilations examined by the FBI included claims the CIA or US Department of Energy had carried out biological warfare tests on the cows, that religious cults were to blame or that "they have some connection with unidentified objects".
Ex-MoD UFO expert Nick Pope said: "These documents show how seriously the authorities took the matter and that they were prepared to debate theories about extraterrestrial involvement.
"The papers also show there is confusion about which part of the government should take the lead. I had similar problems while on the MoD's UFO project.
Continued reading - The sun Article source
FBI is no stranger to Cattle mutilation: