WASHINGTON DC – One of America’s top UFO experts has revealed ‘secret groups’ have been collecting alien remains for more than five decades.

Luis Elizondo, the former AATIP (Advanced Aerospace Threat Identification Program) program manager, shared the terrifying details in his newly published book, ‘Imminent: Inside the Pentagon’s Hunt for UFOs’.

The AATIP is dedicated to exploring ‘unexplained aerial phenomena’ and previously wrote a 490-page report collecting together UFO sightings from around the world.

Elizondo, 52, resigned from the AATIP in 2017 and has since spoken out about the ‘serious national security issues’ UAPs (Unidentified Aerial Phenomenons) pose.

In his book, he revealed a ‘super-secret umbrella group’, including government officials and defence contractors, have been retrieving alien remains and technology for 50 years.

He wrote: ‘We spoke of “purple novas” — projects and programs so secret that not even the secretary of defence or the president would ever know of them.’

Elizondo says government intelligence has pointed to the Roswell, New Mexico incident in 1947 having been two saucers ‘colliding’ – and that was just once instance of non-human bodies being recovered.

He said: ‘Four deceased non-human bodies were in fact recovered from the 1947 Roswell crash.’

Other incidents he mentions of ‘non-human’ recovery missions include December 1950 in Ciudad Acuña, Mexico; and four different occassions in 1989 in Kazakhstan (then, the Soviet Union).

One autopsy report mentioned in Elizondo’s book said the brain of the ‘non-human’ cadaver had no wrinkling on it.

He explained: ‘Rather, what was described was a smooth surface, similar to lower-functioning animals here on earth. It also described a conjoined gut and liver, and a three-chambered heart, like reptiles.’

The cadavers were said to be researched at Fort Detrick, Maryland, a major biological weapons programme military base from the mid 1940s to 1969.

Elizondo’s new book comes at a time of heightened interest in extraterrestrial activity, following last year’s congressional hearings on UFOs.

At those hearings, former intelligence officer David Charles Grusch claimed the US government was hiding evidence of ‘non-human intelligence’.