STOCKHOLM (Reuters) - Arsonists set fire early on Wednesday to a giant straw statue of the Swedish Yule goat, a forerunner to Santa Claus in Sweden, defying security measures for a third year in a row.

Police in Gavle, north of Stockholm, said an unknown number of attackers had torched the goat in the early morning hours, leaving a blackened skeleton standing in the town square.

“It’s a tradition to burn it down,” Lofberg said. “It’s happened an untold number of times since the 1960s ... it’s been burned down more years than it’s survived.”

Burning the goat has been a popular, and illegal, tradition in Gavle since the 1960s when an advertising executive first came up with the idea to endow the city with a giant replica of the goat, a Christmas decoration common in many Swedish homes.

There were no witnesses, but a bottle of lighter fluid was found near the goat’s frame, which stood about 12 meters tall at the apex of its horns, police told Reuters.

“We have some leads,” said Stefan Lofberg, who is leading the investigation for the Gavle police.

Police have tried a range of tactics to stop would-be arsonists, including posting guards near the straw goat, coating it with flame retardant and training security cameras on it.

But vandals have usually found a way around the foils and their assaults have become more elaborate: in recent years the goat has been run over, dragged into a river and attacked by arsonists dressed as Santa Claus and the Ginger Bread Man.

Flame retardant coating thwarted attempts to burn the goat in 2006, but the group sponsoring it then stopped flame-proofing it because of the ugly, brownish tinge its straw took on.

Goats have special meaning in Swedish Christmas tradition. Before Santa Claus became ubiquitous at the turn of the 20th century, men would dress up as goats and hand out presents to well-behaved children. Bad children received lumps of coal.