A team of researchers hope the excavation will yield more evidence about the two Roman bath houses discovered at Whitehall Farm in Nether Heyford.

Last year's project unearthed human remains which have now been carbon-dated between the 5th and 7th centuries and could be the bodies of German mercenaries hired to protect the elaborate estate at the end of the Roman era.

Nick Adams, who owns the farm, revealed the team would be DNA-testing the bodies to establish who they were and where they came from.

Speaking after a public meeting for volunteers on Monday, Mr Adams said: "What we're planning to do is get some DNA samples done on the teeth and then we can try and establish what connection the bodies have with each other, and what part of Europe they are from.

"We can try to establish, particularly the early ones, whether they might have been German mercenaries."

Mr Adams also said this year's dig, which starts in June, is expected to involve uncovering a nearby well, which could unearth some "exciting finds".

The team has been studying the site for more than 10 years after first discovering evidence of a Roman bath house.

Other finds have included preserved seeds, which have revealed the kind of diet Romans and Saxons had in 400-600AD.

Stephen Young, site director of UCN, said: "I think the findings are going to have a big impact in terms of what happened to the site at the end of the Roman period.

"We would like to completely understand the relationship of the second bath house and how this related to the main villa."

The project is looking for volunteers to help with the dig this summer and application forms are available online at www.whitehallvilla.co.uk. Excavations will run from June 15 until July 10.