US researchers have unravelled the mystery of intricate engravings on an ancient Chinese statue of Buddha. The headless statue known as Cosmic Buddha, currently housed at an art gallery in Washington DC, dates back to the sixth century.

The researchers said 3D scans of the statue's surface revealed that the decorative illustrations depict Buddha's teachings and life incidents. "The Cosmic Buddha is wrapped in the simple robe of a monk, but the garment is covered with incredibly complex illustrations of Buddhist stories," according to a statement by Arthur M Sackler Gallery and the Freer Gallery of Art.

Buddha or Gautama Buddha, was born a prince about 2,500 years ago in what is now Nepal. He abandoned a life of comfort at the age of 29 to become a sage, on whose teachings Buddhism was founded. The life-size limestone figure has engravings that highlight his life stories.

Cosmic Buddha
The statue has complex illustrations difficult to discern with the naked eye Freer Gallery of Art

"The decoration on the front and back of this figure's monastic robe features scenes of the life of the historical Buddha and cosmic imagery. On the front chest of the robe, Mount Sumeru, a sacred Buddhist mountain believed to connect heaven and earth, is depicted with two snakes, or naga, entwined around it," the museum said.

"Scenes below illustrate the historical Buddha as a prince before his enlightenment. The tortures of hell appear above the hem," it added.

The statue was built in China during the reign of Northern Qi dynasty (550-577AD) when Chinese Buddhist art witnessed great transformations. The museum acquired it in 1923.

The entire surface of the sculpture is covered with intricate scenes that are difficult to discern with the naked eye but is clearly visible in 3D scans, museum curator Keith Wilson said.

"What make this sixth-century Chinese object exceptional are the detailed narrative scenes that cover its surface. The narrative scenes are spiritual emanations rising from the Buddha himself and illustrate fundamental Buddhist teachings," he said.

According to Wilson, the scenes on the sculpture would originally have been painted, as slight traces of pigment remain on the surface. The statue "may well have been designed to serve as a teaching sculpture, probably in a monastery, where a narrator provided commentary and instruction on the teachings of Buddhism", he added.

Scholars earlier tried to decipher the illustrations by making rubbings of the sculpture's surface using ink on paper, but the method posed a threat to the ancient treasure as ink stains on the surface were left behind.

An exhibition featuring the 3D digital model and images of Cosmic Buddha statue opens in the gallery on 30 January.