The bereaved family of an American boy who was killed in a tornado are drawing comfort from a ghostly image of him they say has appeared in a photograph.

Nicolas McCabe, nine, died when his school was hit by the destructive winds in Oklahoma earlier this year. Six other youngsters were killed at Plaza Towers Elementary School, which had neglected to build a storm shelter due to lack of funds.

Now his father Scott has claimed Nicolas has returned from the dead as a spirit who is watching over his cousin Madison.

Scott believes Nicolas appeared in an image of Madison playing with a sparkler during the 4 July celebrations. When family members saw it, their "hair stood up," Scott said.

In the picture a partial apparition of a figure can be seen behind Madison. The two figures in the image appear distinct from each other - with different skin tone and hair.

But doubters online have ascribed the presence of the spectral second figure to the camera shaking when the image was snapped.

'They can say what they want. I believe. I believe he's watching over us,' said Scott.

Scott McCabe, who believes his deceased son Nicholas is back from the dead as guardian angel PIC: Channel 9
Scott McCabe, who believes his deceased son Nicholas is back from the dead as guardian angel PIC: Channel 9

McCabe described the moment he believes he set eyes upon his deceased son in the photograph.

"I couldn't believe what I was seeing," he said. "Nicolas loved the Fourth of July and he loved firecrackers." Speaking of the figure behind the girl, he said: "It's obviously not Madison. It's obvious there are two people there or one person there and one spirit there.

"My brother, when he saw it, he said the hair stood up on his neck. I was in awe. It touched my heart."