Archaeologists investigating a mass burial of 97 infants at a Roman villa in the Thames Valley believe it may have been a brothel.
Tests on the site at Hambleden in Buckinghamshire suggest all died at 40 weeks gestation, very soon after birth.
Archaeologists suspect local inhabitants may have been systematically killing unwanted babies.
Archaeologist Dr Jill Eyers said: "The only explanation you keep coming back to is that it's got to be a brothel."
With little or no effective contraception, unwanted pregnancies could have been common at Roman brothels, explained Dr Eyers, who works for Chiltern Archaeology.
And infanticide may not have been as shocking in Roman times as it is today.
Archaeological records suggest infants were not considered to be "full" human beings until about the age of two, said Dr Eyers.
Children any younger than that age were not buried in cemeteries. As a result, infant burials tended to be at domestic sites in the Roman era.
Even so, say experts, the number at the Yewden villa at Hambleden is extraordinary.
"There is no other site that would yield anything like the 97 infant burials," said Dr Simon Mays, a skeletal biologist at English Heritage's Centre for Archaeology, who has been investigating the finds.
The ages of the babies were estimated by measuring the length of the bones. The researchers found these were all of similar size.
Dr Mays believes that this points to systematic infanticide at birth rather than death from natural causes, which would have struck infants at different ages.
The dig was on a massive scale but is now buried under a wheat field.
But meticulous records were left by a naturalist and archaeologist called Alfred Heneage Cocks.
More than 300 boxes full of artefacts, pottery and bones were recently re-discovered at Buckinghamshire County Museum along with Cocks' original report published in 1921, and a small photo archive.
The records give precise locations for the infant bodies, which were hidden under walls or buried under courtyards close to each other.
Cocks' original report paid little attention to these remains, which are now being tested for the first time by English Heritage.
The team plans to carry out DNA tests on the skeletons in a bid to establish their sex and possible relationship to each other.
They are also trying to uncover any other information which might suggest a motive for the practice.
The Hambleden investigation features in a new BBC TV archaeology series, Digging for Britain presented by Dr Alice Roberts, to be broadcast on BBC Two in July and August.