© ReutersUNEXPLAINED SIGHTING: A possible UFO sighting as reported by the Journal of Scientific Exploration, is seen in an undated file photo.
The reports, detailing "sightings" of unidentified flying objects and their operators, range from the downright wacky to the intriguing.
Accounts came from people in all walks of life, including air force personnel, commercial airline pilots and passengers on aircraft, and even a New Zealand prime minister took a close interest in one case.
The more than 2,000 pages of documents dating back to the early 1950s had not been due for publication until the year 2050, but were released after requests under freedom of information laws.
Many reports include sketches of flying saucers and aliens, one showing a human-like figure dressed in silvery material with a wide belt, helmet and visor.
One man wrote to a government department in November 1955 to say he had seen "many" flying saucers.
"I and my nephew actually witnessed one taking off," he declared.
The most detailed accounts were from pilots who reported mysterious lights in the sky, providing maps, positioning data, and drawings.
Among those is New Zealand's most enduring flying saucer mystery, dating from December 1978, in which the crew of a cargo plane reported seeing bright lights in the sky above the South Island coastal town of Kaikoura.
Their account was backed up by blurry footage filmed by a news crew for the state-owned broadcaster Television New Zealand.
Mysterious objects also reportedly appeared at the time on air traffic controllers' radar screens but no other aircraft were in the vicinity.
The reports show that the late Sir Robert Muldoon, then prime minister, took a close personal interest in the Kaikoura incident.
Investigators believed the lights of a squid boat could have been to blame but the case was never satisfactorily resolved.
Suzanne Hansen, a flying saucer researcher who has studied the incident, said last night: "It is obviously something we can't explain.
"We don't know what it is, but it is certainly something that is unidentified and non-conventional."
The documents show that every respondent, no matter how outlandish their claim, was treated with courtesy by officials.
While many reports were dismissed as the planet Venus, meteors, weather balloons, and even the Moon, one routine response was: "Thank you for the opportunity to look at your sketches.
"They are returned with thanks."
I was in the UK at that time, but a few years ago, local TV screened a docco on this event, this docco claimed that the camera people who actually filmed this event were brought in from Aussie, which means that the event was over a number of days (well at least 2, one to be seen, aussies imported and another to be filmed). So what type of event lasts over at least 2 nights, in the same location ??
I wonder if the docco is findable on the web, would be interesting to watch!