British Ministry of Defence released the once top secret file last week, together with several other formerly declassified documents.
The information includes the unexplained incident involving a USAF RC-135 plane and a big object. It took place on October 19, 1982, when the plane was snooping on Soviet military activity. The big object reportedly buzzed the aircraft over the Med.
The American crew called for help to the British troops stationed at RAF Troodos, a base on Cyprus, as a UFO reportedly cloaked in a multitude of flashing lights, 20 at a time, zoned in.
The incident reportedly lasted for around 90 minutes. The UFO was spotted on the south of the island and an RAF Phantom, and two US Navy F-14 fighters were scrambled to chase the so-called intruder.
As the three jets approached, the American crew saw the UFO turned away and headed toward the African coast, but the fighter pilots had seen nothing.
Documents show that an investigation was conducted and sent to the US defence bods. Intelligence officers analysed the transcripts of the distress call, tapes, and radar film, but all of these were removed from files.
A suggestion from an RAF worker says that they have a strong suspicion that the UFO was a mirage effect from lights on Israel or Lebanon coast.
However, the results of the joint UK and US investigation are missing in the file.
Dr David Clarke of Sheffield Hallam University was instrumental in the release of those files. He described the encounter as fascinating and puzzling as the US and UK military authorities took it very seriously.