A novelist claimed to have spotted a flying saucer decades before the term was coined by US newspapers, according to a Ministry of Defence (MoD) archive released yesterday.

Eleanor Kaye, author of The Storm Makers and Spooked For Life under the pen name Savanah Thorne, reported seeing an "upside-down saucer" surrounded by lights off the North Cornish coast as a child in 1926.

The alleged UFO sighting came almost 20 years before the first highly-publicised sighting by American Kenneth Arnold in 1947, which led to the widespread description of the craft as saucers.

The release of UFO-related documents by the National Archives began in 2008 in the wake of a flood of requests under the Freedom of Information Act.

The MoD closed down its UFO hotline last year after a round of spending cuts.

The project, which is currently only halfway through, will eventually release tens of thousands of pages to the public.

The latest swathe, which features several dozen sightings from Devon and Cornwall, contains about 5,000 pages and is available online.

Dr David Clarke, author of The UFO Files and senior lecturer in journalism from Sheffield Hallam University, said most sightings were "genuinely reported".

"Lots and lots of accounts have come to light but there is no solid evidence that aliens have landed on Earth," he said.

"The vast majority of people are genuinely concerned that they have seen something they cannot explain - otherwise they would not report it to the police or an air base.

"We can often pin down the cause to a meteor storm or military activity, but unfortunately the MoD have had limited resources and just filed the reports away."

Documents showed that the Cornish writer and member of the Society of Authors wrote to RAF St Mawgan in 1995 to ask if any similar reports had been received.

A reply from the MoD's Air Staff Secretariat said the Armed Forces "remained vigilant" and investigated all unexplained aerial sightings for potential threat.

The letter, which has been redacted to remove all names, said the MoD had received "a small number of reports from Cornwall" and that none had been of concern.

In a case from 1995, a man in Penzance reported a "near miss" over Penwith.

He described two incidents where an "unknown craft" came just yards from colliding head on with an aircraft which was "assumed to be our own".

Another report from Devon described a "very bright silvery object" above the banks of the Great Western Canal at Halberton in Devon.

Dr Clarke added that the released archives were unlikely to satisfy some conspiracy theorists, who would "probably claim that the secret stuff was being withheld".

The documents also revealed that Sir Winston Churchill was accused of covering up a close encounter between an RAF aircraft and a UFO during the Second World War. The former prime minister allegedly ordered that the unexplained incident over the east coast of England should be kept secret for at least 50 years because it would provoke "mass panic".