LONDON (NYTIMES) - In July 2018, Dr Hugh Willmott was overseeing the excavation of an Anglo-Saxon burial site in north-east England when a regional preservation official told him about a potentially more exciting find.

Just down the road, at Tetney Golf Club, a local golf course, workers digging in a small pond with a giant excavator had hit something extremely unexpected: A prehistoric coffin containing the skeletal remains of a man.

When Dr Willmott, an archaeologist and senior lecturer at the University of Sheffield, arrived at the golf course the next day, he found a scene that he said could only be described as "a mess".

Ten to 12 feet (3m to 3.5m) underground, the crew had discovered a waterlogged burial site and an exposed coffin broken in pieces.

Dr Willmott said he quickly realised that he and his team of archaeologists would have to act fast and undertake a "rescue and recovery operation" to save the coffin from further deterioration.

Archaeologists inspected the timbers and discovered it was a log coffin made from a hollowed-out tree that had been buried under a mound.

Using log coffins was "an unusual form of burial" that had briefly been the practice 4,000 years ago in the Bronze Age, said Mr Tim Allen, an archaeologist with Historic England, a public agency charged with preserving the country's history.

Along with the remains was "a perfectly preserved axe" with a stone head and a wooden handle, according to the University of Sheffield.

The ancient timber and axe were placed in temporary cold storage to keep them stable while archaeologists tried to learn as much as possible about them before the researchers begin the conservation process, which could slightly alter the artefact appearance, Dr Willmott said.

Historic England helped pay for the effort with a grant of nearly £70,000 (S$130,000).

The coffin was transported to York Archaeological Trust, where the conservation process was expected to take two years.

Conservationists are still deciding whether to try to put the coffin back together, said Mr Ian Panter, head of conservation at the trust.

The coffin and the axe will eventually be displayed at The Collection, an art and archaeology museum in Lincolnshire, not far from the golf course, according to Historic England.

The remains of the man will stay "in curated care" and are unlikely to be displayed, Dr Willmott said. He added that the bones of the man reveal that he was five-foot-nine (1.75m) - "quite tall" for that era - and that he most likely died in his late 30s or early 40s.

The bones also showed evidence of osteoarthritis, the "result of heavy work rather than old age", Dr Willmott said. "He would have looked like he went to the gym," he said.

The burial he received strongly suggested that the man was an important figure in his community, Dr Willmott said.

"To make a log coffin is a bit of complicated technology," he said.

A gravel mound was constructed over the coffin, which would have required the efforts of many people, not just family members, Dr Willmott said.

The axe was most likely ceremonial, a "symbol of authority", Mr Allen said.

He added that radiocarbon dating could help them analyse the wood so they could determine when the tree was taken down.

The time-consuming burial suggests "this was a society with a hierarchy focused upon certain individuals", Mr Allen said.

Everyone involved in the project agreed not to publicise the discovery until an analysis was done, Dr Willmott said.

The owner of the golf course also agreed to stay silent, he said.

The owner, Mr Mark Casswell, was "quite keen for people not to know, because he thought it might put off business", Dr Willmott said.

"People either get weirded out by dead bodies or they're fascinated by them."