Handprints found near a Blue Mountains train station that an expert said were Indigenous and "culturally significant" have been exposed as fakes created by Riverina teenagers in the 1960s.
The rock art was discovered during work to remove a 20-tonne boulder, which threatened the Blue Mountains railway line in late March, causing weeks of delays for commuters.
But in a letter obtained by the Gazette last week, the non- Indigenous man who created the artwork 50 years ago said he and his brothers were paying homage to local Indigenous culture and he was now keen to "set the record straight".
The man, who lives in the Riverina region and has asked not to be identified, wrote the letter to Indigenous elders and it has been passed along to local historians and the Australian Museum.
In the letter he admits to creating the cave hand prints as a 13 or 14-year-old with his siblings in about 1969. He apologised for the "fuss".
"We loved Aboriginal culture and history and making the handprints was just another of our activities which imitated their culture," he writes.
"We ground some local red sandstone to make powder, mixed it with our saliva, rubbed it on our hands and simply stamped them onto the cave wall. I was amazed an expert did not realise they were not genuine as we did not stencil them, as Aboriginals would have, we just stamped them. We were not keen about putting the mix in our mouths, so we just rubbed it on our hands."
The man said they had had "no intention of offending anyone (and) no idea what fuss it would cause 50 years later".
"As kids we used to roam the bush enjoying its beauty and searching for signs of Aboriginal occupation. We made spears and even ground an axe head from stone".
Gundungurra elder Aunty Sharyn Halls, the secretary of the Gundungurra Aboriginal Heritage Association which has an ILUA (Indigenous Land Use Agreement) over the site, said the experts had "made a terrible mistake and not consulted properly. They were so excited, they jumped the gun".
"People jumped the gun. I drove 500 kilometres to meet this guy recently to confirm the story. Make no mistake this guy is the person who did it when he was a kid with his brothers," Aunty Sharyn said.
The artist said he spoke out as it was "important to maintain the integrity of registered sites and to have them verified by local Indigenous groups before being declared 'culturally significant'."
He also apologised "on behalf of myself and my brothers...for any inconvenience" and hoped he had not offended any Indigenous people.