"The head sculpture is exquisitely crafted. The face is round and plump and exudes a particularly serene expression," Lu said.

The relics were found stacked and embedded in a wall. Judging from its appearance and the materials used, the wall was constructed much later during renovation work, Lu noted, adding that the bricks used in its construction dated back to the Ming Dynasty (1368-1644).

This discovery improves our understanding of the Tang Dynasty statues at the Longmen Grottoes, as well as our knowledge of the history and culture of the Leigutai area, ancient maintenance and reinforcement practices, seismic history, and the economic and social conditions of the time, Lu said.

He added, "It is of great significance for furthering research on the protection of the Longmen Grottoes."

Wang Ru contributed to this story.