When antiques collector Stephen Hibberts discovered a dusty oil painting of Jesus at a fair in Avignon he believed he was buying an unremarkable reproduction that was worth a few hundred pounds at best.

The portrait entitled Noli Me Tangere (Don't Touch Me) was lying awkwardly on the ground where people were forced to step over it. One person even accidentally trod on the frame causing the canvas to be pierced by a piece of limestone.

Yet after studying the painting over many years, Mr Hibberts began to suspect he had uncovered something quite special. Hidden in the image were secret clues which suggested the painting was not only hundreds of years older, but could be a lost Raphael worth tens of millions.

“When I bought it I liked its gothic and rustic appearance,” said Mr Hibberts, 60, who is originally from Stoke on Trent but now lives in Bordeaux, France.

"But it wasn't in the best of nick. I didn't think it would be worth much at all. I'm a realistic man. I'm aware that it is sometimes tempting to see things that aren't there, that you see things you want to see.”