The remains of what could be an Iron Age Highlander, who lived around 2,000 years ago, have been found during an archaeological dig in Caithness.

The human remains, which include a skull and bones, were found this week in the ruins of a broch - a massive stone wall Iron Age roundhouse - at Thrumster, near Wick.

They were buried in a chamber in the wall of the historic building.

Dr Andy Heald, of AOC Archaeology, which leads the dig, said that it was probably the remains of an adult man, though further research was needed to determine that.

Radiocarbon dating is also needed to determine how old the bones are.

"At the moment we have no idea on a date. They could be 200 years old, or 2,000 years old," he said.

"There have been archaeological digs at this same site about 200 years ago and we know they found human remains then - and reburied them later.

"It is therefore really hard to tell if this one has been here for all these centuries, and was buried in the Iron Age on the same spot as where we found it, or if it was reburied during the first dig, or sometime in the centuries in between.

"We know that at another Caithness site at Whitegate human remains, horses and even puppies were placed at a broch 300 years after it was abandoned."

Dr Heald said they knew for certain that the broch was 2,000 years old, but the site has been re-used in later times.

"The Vikings used it, for instance, just as the medieval inhabitants of this area," he said.

"If the remains really turn out to be 2,000 years old, it will be very interesting. It would help us understand the way people dealt with death in a pre-Christian society. It would show us that they buried them - or at least the skull - in or under the house.

"We don't come across human remains that are this old that often, so it would make it a very special find.

"When skulls were found in the 19th century people thought it had to do with cannibalism, which is just nonsense, or were war trophies.

"Hopefully with new techniques we will be able to determine the sex and age of this person, and when he died, so we know if it is indeed an Iron Age hunter, or perhaps a medieval gardener."

AOC Archaeology and Yarrows Heritage Trust have been leading teams of 12 to 15 volunteers on the dig.

A broch - often described as "complex Atlantic Roundhouse" - is an Iron Age drystone hollow-walled structure of a type found only in Scotland.

Although most stand alone in the landscape, some examples exist of brochs surrounded by clusters of smaller dwellings.