The force today issued an appeal for information as it revealed a group of young people had been seen pushing a rock at the top of one of the beauty spot's famous rock formations last Friday.
He said: "A group of five young people were seen pushing a rock at the top of one of the crags. This resulted in the rock falling from the crag causing damage to the crag face.
"The damage this has caused is irreplaceable and it is now in a potentially dangerous condition.
"The incident has not only caused considerable damage to both the rock and the crag face, but those responsible also put themselves in danger and have created a potential hazard for other visitors to Brimham Rocks."
The group were seen pushing the rock at around 8.45pm on Friday, June 1.
Fire crews from across the district were called to battle a blaze at the beauty spot last month, although there has been no suggestion that the two incidents are linked.
Alternatively, email [email protected] to pass on information.