A 2,000-year-old highway, a mausoleum and an aqueduct have emerged from the dust just outside the Italian capital, making experts consider redrawing maps of ancient Rome .

Electric company workers stumbled on the finds in the early summer as they began digging near the suburban area of Casale di Malafede, preparing to install new street lights on the main road from Rome to the sea .

It appears the old Roman road, made of blocks of black basalt and wide enough to carry two lines of traffic, was a second, previously unknown, link between the capital of the empire and its port at Ostia .

It had long been assumed that there was only one road between Rome and the port, the Via Ostiense, which still exists today and carries heavy traffic from the modern city to the sea .

According to archeologists, the presence of the second road could mean a large area outside Rome was densely populated once and hence needed a second communications artery. Measuring some 4.5 metres across, the road is as wide as the key 'consular' roads, such as the Appian and Aurelian Ways, built by Romans to connect the city to the rest of Italy and Europe .

The theory of a previously unknown town, possibly something like a modern suburb, is backed up by the presence of the mausoleum and numerous poor people's graves by the side of the road .

"It is well known that Romans buried their dead beside the roads outside their settlements. So you have to ask whether there was once a thriving town between Malafede and Ostia," said ancient history lecturer Marco Guidi in Rome daily Il Messaggero .

The discovery of the aqueduct going from Malafede to Ostia neither proves nor disproves the idea that the area was heavily populated, although it would have required maintenance. The head of archeological digs at Ostia Antica, the old Roman site, has called on the government to stump up the 70,000 euros needed to throughly excavate the site at Malafede .

He said the area may offer more clues to the geography of the region outside Rome .