Greenpeace were forced into an apology this week after a PR stunt at the historical Nazca lines site in the Peruvian desert drew intense criticism from Peru's government.
In the stunt at the UN World Heritage site in Peru`s coastal desert, activists laid a message promoting clean energy beside the famed figure of a hummingbird comprised of black rocks on a white background.
The enviromental group has announced that its executive director, Kumi Naidoo, will travel to Peru on Monday to apologise for the stunt.
Peru's deputy culture minister Luis Jaime Castillo called it a "slap in the face at everything Peruvians consider sacred".
Mr Castillo said "not even presidents", are allowed without authorisation where the activists set foot, and those who do have permission must wear special protective shoes.
Another senior Peruvian official told The Associated Press that his government would seek criminal charges against Greenpeace activists who allegedly damaged the lines by leaving footprints in the desert adjacent to the ancient marvel.
The altitude and arid conditions of the Nazca plateau mean that imprints left by errant human interference can remain undisturbed for decades.
Aida Vila, Greenpeace climate change director, said:
The Greenpeace delegation chief to the climate talks in Peru, Martin Kaiser, said none of the people involved in the action had been arrested.
“I think activists are always taking responsibility for what they are doing,” he said. “We clearly underestimated the sensitivity of the situation.”
It is unclear if they will face internal disciplinary action for their actions, but if charged by the authorities could face up to six years in jail.
A UN World Heritage Site, the Nazca lines are huge pictographs depicting living creatures, stylized plants and imaginary figures scratched on the surface of the ground and only fully visible from the air between 1,500 and 2,000 years ago.
They are thought to have had ritual astronomical functions and some believe them to be ancient landing strips for extra-terrestrial visitors.