Archaeologists have uncovered evidence of a 1,200-year-old massacre in Guatemala that could provide clues to one of the enduring mysteries of central American history - the precipitous collapse of the once glorious Maya civilisation.

The team spent the summer excavating ruins of the ancient city of Cancuen in central Guatemala and dug up at least 45 skeletons belonging to members of the Mayan royal court who appear to have been ritually slaughtered by an as-yet unknown horde of assailants.

Among the bones were those of the Mayan king Kan Maax and his wife, identified by their jewellery, headdresses and other precious artefacts. At least a dozen others showed signs of having been ritually dismembered and thrown into sacred spring waters - presumably as a way of wiping out both the leadership of Cancuen and the city itself.

Many of them appear to have died as a result of sharp spear jabs to the throat, suggesting summary execution on a grand scale. The attackers also chipped the faces of statues and religious monuments.

The ruins of Cancuen were discovered more than a century ago, but their significance as a possible centre of the Maya civilisation only became apparent five years ago, when a vast palace complex was found.

Scholars have long debated how, and how quickly, the Maya civilisation came to an end. The evidence unearthed by the archaeological team, led by a scholar from Vanderbilt University in Tennessee and funded by the National Geographic Society and the National Endowment for the Humanities, makes the strongest case yet the collapse was the result of a vicious war.