The heavily guarded Area 51, deep in the Nevada desert, is at the centre of many alien-related conspiracy theories.

It is claimed that alien flying saucers crashed on Earth, such as the alleged 1947 Roswell incident, and that the wreckage and even corpses were taken to Area 51 for experimentation and to be analysed away from public view.

One theory suggests that USAF scientists have tried to emulate the alien technology to create their own top-secret spy craft capable of travelling into space at the base.

The images obtained by the pair show what looks like a water tower, several complexes, and vehicles moving around.

There is no sign of any stored UFOs or alien activity in the pictures.

Thousands visit the remote area of Nevada every year in the hope of seeing ETs.

Many more sceptical people believe Area 51 is so top-secret, because it is where the USAF designed and tests experimental new spy planes and air craft.

Nigel Watson, author of the UFO Investigations Manual, said: “Area 51 has always been a magnet for those who believe the US Government knows a lot more about UFOs than they are prepared to reveal to the public.”

The area is so mysterious that US presidential hopeful Hillary Clinton made a shock promise that she would declassify all secret Area 51 files.

And more recently alien hunters claimed they had found a UFO inside a climate controlled hanger near Area 51 using Google Maps.

Source: Express.co