Repair work has severely damaged the natural image of the Great Wall in Suizhong county, Liaoning province, despite the work's strengthening effect, officials said.[Photo by Zhang Shiyao/Asianewsphoto]

On the surface of some steep parts, a small quantity of concrete was added to the traditional material, which was not clarified in the project plan, she said.

Fu Qingyuan, senior engineer with the State Research Institute of Cultural Heritage who was on the investigation team, said, "Concrete is internationally considered a new material that can be added to traditional material to improve the effect in restoring cultural relics."

Song said the administration should have supervised the concrete restoration of the Damaoshan section of the Great Wall after examining and approving the project's plan, which did not detail materials or methods.

Lu, the head of the investigation team, said in the report that the Cultural Relics Bureau in Liaoning needs to organize experts to fully examine the repair work to see whether there are more problems. Those responsible will be punished for the damage to the Great Wall's image, she added.