ETRUSCAN ARTIFACTS FOUND BY ACCIDENT -- LOOTERS KEPT THEM HIDDEN FOR YEARS

The robbers were not professional tombaroli, the looters of ancient sites who have over the centuries despoiled countless graves in Italy. They were people, the authorities said, who had stumbled onto a trove of important Etruscan artifacts a decade ago while digging to build a garage in a villa just outside the city center here. Rather than notify authorities, investigators say the looters divided up the stash and looked around for years before trying to cash in on their good fortune.

But two years ago, when the police were searching a home in Rome, they turned up a photograph of what appeared to be an illicit artifact. That investigation eventually led them to Perugia, and when the looters appeared ready to sell the artifacts this year, members of the police art theft squad moved quickly.

In a news conference announcing the confiscations, Italian authorities described the seized objects — 21 delicately carved travertine marble urns dating to the Hellenistic period — as one of the “major finds” of recent history. Under Italian law, they are now property of the state and will eventually be installed in Perugia’s archaeological museum. But archaeologists bemoan that they still lost something precious: the context the artifacts were found in.

In covering their tracks, the looters effectively wiped out the sort of information — the size of the tomb, the number of rooms, how the various urns and other artifacts were arranged — that scholars scour for information to reconstruct ancient civilizations. “And we still don’t know where the tomb was — we think they built over it,” said Luana Cenciaioli, a local official with the cultural heritage authority, which has begun an exploratory dig in the area where it believes the tomb was located.

Italy’s artifact-rich soil is forever delivering up evidence of past civilizations — when foundations are laid, or new roads or sewers are built — and authorities have long struggled to counter the trafficking of such artifacts. Still, heightened investigative activity and high-profile Italian court cases have dampened the market for looted artifacts, and museums around the world have tightened the rules on how they collect antiquities.

The urns confiscated this year were identified as belonging to the Cacni family, a wealthy local clan, and date from the third and second centuries B.C. The high quality of the urns, experts say, suggests that the family supported the political transition of Perugia into the orbit of Rome, which had vanquished the Etruscans at the Battle of Sentinum in 295 B.C. “From a historical point of view they are important,” said Gabriele Cifani, an antiquities expert at the University of Tor Vergata in Rome, who assisted in the police case.

Unfortunately, the diggers’ inexperience caused them to damage some urns as they were roughly removed from the ground. And some of the bright hues — including golden decoration — that enlivened the travertine and are so typical of Etruscan art were left to fade away, a process that a qualified restorer could have impeded. No one has been arrested or named in the case, but investigators who directed Operation Iphigenia, as it was named, have identified five suspects and view them as “white-collar” types. (Iphigenia was the daughter of Agamemnon, who sacrificed her so his ships could sail to Troy. The myth was a popular motif on funeral urns at the time the artifacts were made.)

If the suspects are charged and convicted, they could face up to 10 years in prison. But the case still might not get to trial because the statute of limitations for the crimes of which they are suspected — illegal excavation and receiving stolen goods — may run out. Last week, Massimo Bray, Italy’s culture minister, pledged to push for a bill to toughen penalties for cultural property crimes.

Had the discoverers notified the authorities when they stumbled upon the tomb, they could have benefited from a finder’s fee — 25 percent of an object’s market value for the person who found it, and 25 percent to the person on whose property it was found. Ms. Cenciaioli estimated that the average market price for an urn would be around 40,000 euros (about $52,000) — less for those without decoration, more for those with — meaning the finder’s fee could have topped 10,000 euros (about $13,000) for one urn.