Southern Water has revealed it uncovered two ancient skeletons during sewer replacement works in Ramsgate, Kent in 2016.
Working with partners Archaeology South East (ASE), a team of scientists used a method called Carbon 14 dating to determine the age of the bones.
It found both skeletons were from Roman times – one was dated to AD 428 to 630 the other to 200 to 239 BC.
The date ranges encompass two periods of significant change in the southeast British Isles: the end of the Iron Age and the end of Roman occupation.
Archaeology South East are employed by Southern Water as their archaeological advisers and consultants.
Neil Griffin, from ASE, said: “Southern Water contact us to understand the risks of encountering archaeology on any of their schemes.
“The more information we have, the more we can learn about the past, the more we can design research strategies for future works.”
ASE also filmed the reconstruction of one of the skeletons. Now the investigation into the skeletons is complete they will be re-buried in a safe location close to where they were found.