WASHINGTON -- With much fanfare, US television network CNN beamed its correspondent in Chicago into its New York studio during the night of the US presidential election using what it said was a hologram.

Turns out it may not have been a hologram, after all.

The Canadian Broadcasting Co. was the first to report that the technique used by CNN to make it appear as if reporter Jessica Yellin was hovering in space in the New York studio was not a three-dimensional hologram.

It said that Yellin was not actually visible in the studio to CNN anchor Wolf Blitzer as a projected 3D image but only to viewers at home on their television screens.

Hans Jürgen Kreuzer, a professor of theoretical physics at Dalhousie University, in Halifax, Nova Scotia, told CBC the image was a tomogram, which are images that are captured from all sides, reconstructed by computers, then displayed on screen.

"The images were simply added to what viewers saw on their screens at home, in much the same way computer-generated special effects are added to movies," CBC said.

CNN said it employed 20 computers and 40 high-definition camera feeds with a green-screen virtual-set environment to create the image Tuesday night in the CNN Election Center in New York.