National security scholars at George Washington University have some good news and bad news for UFO buffs – the US Government has finally confirmed the existence of Area 51 in Nevada, but it makes no mention of little green men or alien spaceships.

The Government acknowledged the existence of the mysterious aviation test site known as Area 51, a remote installation about 130 km northwest of Las Vegas, in a newly declassified CIA history of its U-2 spy plane programme.

After decades of extreme secrecy surrounding the site, stoking conspiracy theories about UFOs and experiments on alien spacecraft, the CIA lifted its veil on Area 51 in response to a public records request from George Washington University scholars in Washington, DC.

Publicly released online on Thursday by the university’s National Security Archive, the 400-page CIA history contains the first deliberate official references to Area 51, also known as Groom Lake, as a site developed by the intelligence agency in the 1950s to test fly the high-altitude U-2 reconnaissance plane.

Other top-secret aircraft were tested there later, including the supersonic reconnaissance A-12 aircraft, code-named OXCART, and the F-117 stealth ground-attack jet, said archive senior fellow Jeffrey Richelson, who asked for the CIA’s U-2 history in 2005.

A newly revised document restoring numerous references to Area 51 that had been redacted in earlier versions was furnished by the CIA a few weeks ago, he said.

“It’s the first time that there must have been a senior-level decision to acknowledge the term ‘Area 51’ and its specific location,” he added.