The frescoes were stolen from a tomb in Paestum during a clandestine dig in the 1990s and police feared they had been lost forever.
But in May last year they discovered the frescoes in the warehouse of a Swiss businessman in Como, who bought the pieces without inquiring about their provenance.
“Without doubt these artefacts belonged to Paestum,” said Gabriel Zuchtrigel, director of the archaeological site of Paestum.
“But we don't know which tomb they belonged to because the site was raided by robbers – something which is devastating for real archaeology.”
The five frescoes were originally one whole piece but were separated at some point, possibly during their removal.
The stunning frescoes depict detailed scenes of the daily life of a member of the pre-roman Lucanian people. The Lucanians were an Italic people who conquered the ancient Greek city of Paestum – on the Tyrrhenian coast's modern-day Campania - in the fifth century BC.
Judging from the scenes shown, the young man buried in the tomb was once a member of the Lucanian aristocracy and most probably a military commander.
The scenes depicted include one of the young commander returning home from battle riding a chariot filled with the spoils of war.
Other pictures show what were perhaps other important interests in his life: food, drink and women.
The frescoes can be seen at the Museo Storico Dell'Arma Dei Carabinieri in central Rome.