What is being billed as the biggest illegal waste dump in Europe, containing everything from chemicals and plastics to discarded construction materials, has been uncovered just north of Naples.

Local environmental police said they found waste leaking up toward the surface from buried containers, some of it flammable. The waste is “exceptionally hazardous, and would have been expensive to treat before being disposed of in the correct way. That’s why it was just dumped here,” a police spokesman said.

The dump, discovered by an Italian journalist, has been linked to the Mafia. “We used images dating back to the 1960s, have compared them with recent pictures and have discovered lots of new overgrown mounds,” the journalist, Salvatore Minieri, told Italian news media. Using a drone and shovels, “we discovered that the soil beneath the surface was blue or pink,” said Minieri.

A member of the Mafia is said to have told police several decades ago that illicit dumping was taking place in the Naples region. Local residents are now demanding a full investigation into the kind of waste buried and how big a risk does it poses to their health.