A fisherman who claimed to be abducted and then rejected by aliens for being "too old and infirm" and two policemen who spotted a spaceship hovering over a road are among a list of close encounters revealed by Britain's very own X-file investigator.
Nick Pope was employed by the British Ministry of Defence to investigate alien abduction and sightings as part of their now defunct UFO Project.
Over the years, he had to analyse hundreds of possible sightings and encounters to decide whether they had any merit or were a threat to Britain's "territorial integrity".
He worked alone but could call on the help of a range of other Government experts to check the voracity of the claims, which came from a diverse number of sources including ordinary members of the public, the police and servicemen.
While none showed real proof of the existence of extra terrestrials, many remain a mystery to this day.
Now for the first time he has compiled his top 10 most creditable and bizarre stories that crossed his desk during his time deep in the heart of Whitehall.
"The vast majority of the people were mistaken," said Mr Pope, 45, who worked for the department between 1991 and 1994.
"Most of them turned out to be aircraft lights, weather balloons or meteorites. Quite a lot of times especially at night alcohol had played its part.
"Clearly other people were delusional and others even showed signs of mental illness. But some people may have seen something very interesting and as yet unexplained."
He said that during the department's operating life – from 1950 to 2008 – the most convincing sighting remains when American air force personnel spotted space craft hovering over their base at Rendlesham Forest in Suffolk.
At the same time radiation levels around the aerodrome spiked.
"This was Britain's own Roswell," said Mr Pope referring to a famous incident in the USA when the air force claimed to have seized a flying saucer and which continues to cause debate among UFO experts.
"It remains totally unexplained."
Other creditable and unexplained stories include when two police officers reported seeing a "Saturn-like UFO" over in North London after being called out by a member of the public.
There were a number of sightings by commercial airline pilots who claimed to have had near misses with UFOs and a meteorological Officer who witnessed a huge, triangular-shaped craft fly slowly over RAF Shawbury, near Shrewsbury, Shropshire.
Other stories were more bizarre and on the surface, less creditable, said Mr Pope.
A former Army officer Alfred Burtoo, 73, claimed he was abducted in 1983 by little green men while out fishing.
He said he was taken on-board the ship, but heard a voice say "You can go. You are too old and infirm for our purpose".
He told his wife he had seen a UFO but did not mention being taken on-board, because he thought she would ban him from fishing.
In Somerset, a couple saw a UFO over a field and when they investigated they found cows standing silently in the middle of the field, facing each other in a perfect circle as "if in a meeting".
Mr Pope said some sightings by airlines pilots seemed suspiciously like missiles or prototype drones which could be "foreign powers testing our space" or top secret projects.
However, neither the MoD nor the Civil Aviation Authority ever found an explanation.
Mr Pope said that his time on the project made him less sceptical about possible aliens.
"I went in thinking that it was all rubbish but came out thinking actually some of this is quite interesting," he said.
"But when X-files television series came out I was the victim of some fairly good natured ribbing."
Mr Pope compiled his list to coincide with the release on Blu-ray and DVD of the film Battle: Los Angeles on 11 July.
- Richard Alleyne© Telegraph.co.uk