When Israeli authorities wanted to expand the Megiddo Prison, they tapped their captive labor pool and put dozens of inmates to work digging inside the compound here that is ringed with coiled razor wire and guard towers.As is common practice in Israel, the site underwent a check for possible archaeological ruins before heavy equipment could be moved in. Last week, the inmates discovered a Christian religious site that Israel’s Antiquities Authority said may date to the third century A.D. and could be the earliest Christian church unearthed in the Holy Land, and possibly one of the earliest in the world.
Dozens of journalists were invited into the prison on Sunday to view two well-preserved tile mosaics, which include detailed inscriptions in Greek and which the authority said served as the floor of the church.

“It is for sure the earliest church in Israel that we know of,” said Yotam Tepper, the archaeologist in charge of the dig, which began seven months ago.

The announcement was met with deep skepticism from some scholars of early Christianity.

The traditional view is that Christian churches did not begin to appear in the region until the fourth century A.D., the result of Emperor Constantine’s edict in A.D. 313 that Christians could worship freely in the Roman Empire. Before that, Christians were often persecuted. They worshiped clandestinely and were not able to build public houses of worship, these scholars say.

“For people who study this, it would be very hard to accept that there is a Christian church here that dates to the third century,” said Joe Zias, an anthropologist and a former curator with the Antiquities Authority. Mr. Zias, who has not seen the site, added, “My gut feeling is that we are looking at a Roman building that may have been converted to a church at a later date.”

When citing the earliest churches in the region, scholars most often point to the Church of the Nativity in Bethlehem, the spot where tradition holds that Jesus was born, and the Church of the Holy Sepulcher in Jerusalem, built where Jesus was crucified and entombed, according to tradition.
Those churches, built a few years following Constantine’s edict, have been damaged and rebuilt many times over the centuries, and were well documented by the early chroniclers of the Christian church. At Megiddo on Sunday, beneath a black tarpaulin, Israeli prisoners in brown jumpsuits washed down the mosaic while Mr. Tepper and his colleagues from the Antiquities Authority made their case. Pottery shards from cooking pots and wine jugs resting on the mosaic have been dated to the late third century A.D., suggesting the mosaic – and presumably the church – was already in place at that time, he said. The style of the Greek lettering in the three inscriptions point to the same period, he said, and the structure does not follow the traditional building pattern for churches that emerged in the fourth century.

The floor is about 30 feet by 15 feet and has two mosaics, consisting of small black and white tiles in geometric patterns. Two fish, a symbol widely used in early Christianity, adorn one.
In the center of the floor is a base that may have supported a structure used in worship services, Mr. Tepper said. Nearby, one inscription reads, “The God-loving Aketous has offered this table to the God Jesus Christ, as a memorial,” according to a preliminary translation by the Antiquities Authority.
Another inscription says a Roman military officer, Gaianus, “having sought honor, from his own money, has made the mosaic.”

But Mr. Zias said it struck him as strange that a Roman military officer would take credit at a time when the Roman authorities prohibited practicing Christianity. “If I were a Roman soldier in the third century, I certainly wouldn’t want my name on it,” he said. “This would not have been a good career move. In fact, it sounds like the kiss of death.”
If the Megiddo site does date to the third century, “then I would ask why it was not reported or discussed by early church historians,” said Yiska Harani, a historian with expertise on Christian pilgrimage to the Holy Land. “How did they overlook a successful place of early worship?”
Both Israeli and Palestinian prisoners are held in Megiddo, though only Israeli inmates, 60 to 80 at a time, worked on the archaeological dig, prison officials said. The intention was to build additional cells on the site, which had been an asphalt-covered area where prisoners were being housed in tents.

In Israel, many archaeological finds on construction sites are deemed to be of no real value, and construction is allowed to proceed. In this case, archaeologists were well aware of the rich history of Megiddo, also known as Armageddon, the place where the Christian Bible says the ultimate battle of good and evil will be waged. In ancient times, it was the site of many major battles and a crossroads for travelers. Today, the prison, alongside a major roadway in northern Israel, is surrounded mostly by farm fields. Mr. Tepper said no decision had been made on the fate of the site. He said he hoped it could become a small museum, while acknowledging the problems of doing so inside a prison. “We just don’t know what will happen at this point,” he said.