UFO Reports: Any Truth to Britain's Real X-Files?

March 4, 2011 — -- Alien abductions, flying saucer sightings, mysterious lights and even extraterrestrial autopsies -- they're all in the real-life X-files released by the British government this week.

As part of a continuing effort to declassify government reports related to unidentified flying objects, the U.K.'s Ministry of Defense and The National Archives this week released about 8,500 pages of UFO-related documents, illustrations, letters, and parliamentary debates from 2000-2005.

Some of the files describe paranormal reports that turned out to be mere pranks; other stories of intergalactic proportions were ultimately found to have earthly explanations. But the British government said 5 percent of the cases remain unsolved.

"The official agenda is, I've been told, on both sides of the Atlantic, is that gradual disclosure has to be the way," Timothy Good, a UFO expert and believer, told ABC News' "Good Morning America."

In one account, a British man said he believed he may have been abducted by aliens from his London home in 1999. He said he saw an aircraft hovering over his house and then woke up the next morning to find he had lost a period of time.

The Ministry of Defense responded to his report saying that the aircraft was probably an "airship" and the so-called missing time period was likely the result of turning the clocks back for daylight savings time.

In another report, a retired Royal Air Force (RAF) officer described an "unusual atmospheric occurrence" in Sri Lanka in March 2004. He said he heard a clap of thunder and then saw a doughnut-shaped cloud in the sky that "did not rise but headed from the high atmosphere towards the earth."

Other files include civilian and military reports of "cone-shaped" objects and unusual flashing lights in the sky.