Garry Wood and Colin Wright claim they were knocked out and examined by extraterrestrials after their van was ambushed by a flying saucer near Edinburgh in 1992.
Their story is being made into a movie called A70, named after the road on which they were travelling. Starring Lord of the Rings actor Billy Boyd, it is due for release this year.
However, it has emerged that, rather than being dismissed as Holywood fantasy, the alleged encounter was investigated by the Ministry of Defence's UFO desk.
Mr Wood, 33, from Edinburgh, was driving a car to Tarbrax, South Lanarkshire, accompanied by Mr Wright, 25, when the incident is said to have happened as they passed the desolate Harperrigg Reservoir.
The documents are made public today alongside other claimed UFO sightings north of the Border. In the Harperrigg incident, it was claimed Mr Wood "was driving along the A70 when the object dropped a curtain of white light in front of the car".
It adds the ambulance technician "and his friend blacked out for what seemed like 10 to 15 seconds. He thought he had died. When he woke up the car was facing the other direction on the wrong side of the road.
"When he checked his watch he had lost about one hour".
The report notes the UFO was 20ft high. A hand-written note records it was: "Black. No Lights. Round at bottom. Three parts to it. 30ft wide."
The documents state the pair reported their claims to the police, a doctor, psychologist and a local university, although the institution is not named.
Although the report does not cover the aftermath of the incident, it has previously emerged both men underwent hypnotic therapy.
The process is said to have revealed the aliens experimented on the men.
Mr Wood later claimed: "I saw three creatures coming towards my car. I felt intense pain, like an electric shock. Then I was in some room.
"I saw these things like wee men moving about, doing something to me. I could only see up. Then this 6ft creature approached.
"It was white-grey in colour with a large head and dark eyes with a long, slender neck, very slim shoulders and waist.
"There were either ribs or folds of skin on its body. The arms were like ours but there were four very long fingers.
"The little ones were about 3ft tall and seemed to do all the work while the big ones did the communication."
He said one of the aliens spoke to him and said: "Sanctuary – we are here already and we are coming here."
Mr Wood also claimed a red-hot poker-like object was put into his eye, and he was surrounded by other crying humans as the aliens carried out their examinations.
The screenwriter of the planned movie, A70, said Mr Wood was involved in the proposed film which is being made by film producers DBR Entertainment.
In other claimed UFO sightings, the crew of a plane between Aberdeen to Edinburgh reported a bright light rising through the air from their cockpit in December 1996.
In February 1999, an air traffic controller at Prestwick Airport and a police officer spotted a UFO, described as a two large white or yellow lights and the unidentified object was reportedly seen on the airport's radar systems.
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