Stalactites and stalagmites in an ancient NSW cave system have allegedly been damaged, with police launching an investigation.
Police allege the Jillabenan Cave was broken into and vandalised between Sunday, October 17 and Saturday, October 23.
"A padlock securing the doorway into the cave was removed, and the power distribution board was also damaged," a NSW police spokesperson said.
Some parts of the Yarrangobilly cave system are more than 400 million years old, with the Jillabenan Cave dating back around two million years, according to the NSW National Park and Wildlife Services.
Former Kosciuszko National Park manager Ross McKinney said the alleged damage was appalling.
"The Jillabenan Cave is one of the beautiful highlights of that cave system that attracts so many visitors."
Andy Spate was formerly employed by National Parks to manage their caves and said, while the damage did not seem as extensive as he first thought, it was a poor act.
"The photos, while showing some damage, show it's not as extensive as I feared," he said.
"But even so, it's not a good act."
He said it was not the first time this kind of incident had occurred in the caves.
"I'm shocked rather than surprised," he said.
"It's happened before at Yarrangobilly, quite some time ago now."
Police are urging anyone with information to come forward and contact Crime Stoppers on 1800 333 000.
