BRITONS may have been prisoners in one of the first concentration camps, as well as being the inventors of the modern version.

It has been accepted that the British devised the camps in South Africa during the Boer War. Now it appears that Ancient Britons may have been incarcerated in something similar after fighting the Romans 18 centuries earlier.

Archaeologists have long puzzled over who were the original inhabitants of circular buildings at Vindolanda fort on Hadrian's Wall, which were first discovered in 1931 by Eric Birley. Professor Birley's son Robin, director of the Vindolanda Trust, near Haltwhistle, Northumberland, said yesterday: "No other Roman fort has circular buildings like these. We have discovered the whole of the 2nd-century fort was flattened for these huts and a new garrison."

Mr Birley thinks there could have been up to 200 huts, built back-to-back in rows of five and holding up to 1,000 people. He said: "We know that the Romans were putting down a native rebellion in Scotland between Edinburgh and Aberdeen from 208 to 211. It appears they took hostages from the defeated tribes. If these had just been male prisoners they would have been kept in barracks, but each hut is big enough for a family. They are very similar to native huts ­ about six metres in diameter. They had ovens and hearths which suggest they held family groups.

"Also, they had stone foundations and floors, probably built by the Romans, and would have had wattle-and-turf walls built by the natives.

"They may have been here only six months before the huts were destroyed and the new fort built on top. We assume the people were sent home."

Diggers found no evidence of pottery or jewellery associated with Roman life around the buildings. Soil sample analysis is still awaited.