Deep in a labyrinth of dank tunnels, in the heart of Rome’s oldest and largest catacombs, archaeologists have discovered an exquisite set of 1,600-year-old frescoes painted to commemorate the city’s early Christians.

Experts used the latest laser technology to uncover the centuries of grime which had rendered the frescoes invisible.

The discovery has shed new light on the process by which wealthy Romans shifted away from their pagan beliefs and embraced the new religion of Christ in the fourth century AD.