Ever since the invention of cameras, images of ghosts are becoming more and more frequent. The advancement of recording technology is perhaps the single greatest thing to happen to paranormal investigations in centuries.

Recently, cameras proved their worth once again when they captured some shocking footage at a US high school.

Pocatello High School Ghost

The footage is shaky at best, but is a recording of a computer monitor watching security surveillance images from a December evening at Pocatello High School, Idaho.

Nine cameras watch the vacant halls of the building, as shown in the video. Everything seems normal at first: The lights are on, the floors are polished and there's not a soul in sight. However, soon something goes awry with the lighting. Everything starts to flicker. On, off. On, off. It seems random and chaotic.

The person recording these events zooms in on the center image - a shot from the school's upper hall. It seems empty at first, but then something moves. A ghostly figure, barely a shimmer, is at the drinking fountain. It walks over to a bathroom, then up the hall.

Where some ghostly images could be put down to dust or other particles on the lens, there's no mistaking that this translucent shape is a humanoid figure.

Ghosts have been reported at Pocatello for some time. In fact, co-founder of local paranormal investigation group SPIRO, John Brian - who claims the footage appears '100 per cent authentic' - has had dealings with spirits in the past in that very same hallway.

"Our equipment came up missing off the table and a week later, a custodian found it on a window sill in a stairwell," he told the Idaho State Journal. The window sill was so high, he stated, that it would have taken a ladder to get up there.

So is Pocatello High School a haunted site? And if so, why is the spirit lingering? Hopefully further investigation will uncover answers.