Almost 50 years ago, archaeologists searching for the ruined house of Augustus found a tiny clue buried deep in 2,000 years' worth of rubble overlooking the Forum in Rome.

The single fragment of painted plaster, discovered in masonry-filled rooms, led the experts to unearth a series of exquisite frescoes commissioned by the man who would later become Rome's first emperor.

On Sunday following decades of painstaking restoration, the frescoes in vivid shades of blue, red and ochre went on public show for the first time since they were painted in about 30BC.