When builders started digging up the ground beneath the Yorkshire Museum to carry out refurbishment works, all they expected to find was rubble and dirt.
But instead they discovered the skeleton of a powerfully-built Roman gladiator, who had been stabbed to death at least 1,600 years ago.
And the discovery, made at just 30cm below the building's foundations, could prove to be the key clue in the search for York's Roman amphitheatre.
The spot where the skeleton was found has long been thought of as one of the prime locations for the ancient construction, which would have been built when York was the Roman capital of the north.
Experts discovered that the skeleton belonged to a powerful, athletic male who was stabbed at least six times in a fatal attack, including a powerful sword blow to the back of the head.
They believe it is possible that the Roman could be a disgraced or defeated gladiator whose body was thrown out with the rubbish after his brutal death.
Andrew Morrison, head curator of the Yorkshire Museum, said: "This was a huge man for the Roman period who died a violent and bloody death.
"The physical evidence reveals he was a swordsman and that his body was literally dumped with the rubbish – there was no hint that he had been buried in a ceremonial way.
"But what is really interesting to us is that he was found in this area, which is not associated with Roman burials and that many believe could be where York's amphitheatre was located.
"It is far from certain but it could well be the case that this man was a disgraced gladiator who was brutally killed and then left to rot."
Experts from York Osteoarchaeology, an independent contractor specialising in human skeletal remains, found that the man would have been around 5ft 10in – a couple of inches taller than the average height of a Roman – and was aged between 36 and 45 when he died.
The scientists discovered that he would have been a very muscular man, with lesions in his vertebrae suggesting spinal stress, possibly through lifting heavy loads. His arms are well developed and, similar to other gladiators found in York, bear all the hallmarks of repetitive sword training.
They also found the man met a most barbaric end. There are six blade injuries on the skeleton which, because there are no signs of healing, must have been delivered at death. There is a cut to the lower vertebrae of the back bone, a slash to a lower right rib and two slashing marks which penetrated the jaw, causing it to fracture.
Experts believe this is evidence of a sword slicing through the jaw and then getting stuck, with the attacker then twisting the blade to get it free and breaking the jaw bone in two.
The skull had three blade injuries. One was a superficial wound to the top of the head, the second cut into the right side of the skull in two places and the third, probably the fatal blow, was a powerful stab wound to the back of the head.
The Roman was found in January as work on the museum's 2m refurbishment got under way. He was among animal bones and broken pottery in an area which has for a long time puzzled archaeologists as it is close to the Roman Fortress, on what was a very flat expanse of ground.
Because it is also a key medieval site, the precinct of St Mary's Abbey, excavation at the location has been limited and meant that the Museum Gardens remains one of the few untouched areas in the city large enough to house the amphitheatre.
The museum said yesterday that there were no plans for further excavations at the moment, but added that part of the skeleton had been sent away for carbon dating to establish the Roman's exact age. The remains are going on display at the Yorkshire Museum from this week.
Decoding secrets of the skeleton
Analysing a skeleton that has been buried for more than 1600 years takes less hi-tech equipment than might be expected.
But, said Malin Holst, who carried out the study on the murdered Roman, a keen eye and experience is essential.
Ms Holst, director of York Osteoarchaeology, said of the killer blows: "A wound is recognisable as one side is sharp and smooth and the other edge is rough."
She added: "To work out his age we looked at the degeneration of his joints and wear to his teeth.
"You can tell height by measuring a long bone like a thigh or shin bone. We knew he was muscular as the bones were shapely."