Experts have this week identified a recently discovered site in China as an early Christian burial site with origins in the Nestorian Church.
The researchers date the site to some time between the fourth and tenth centuries, making it the earliest known Nestorian burial place in China, UCANews.com reports.
The site lies in the Longmen Grottoes, a UNESCO World Heritage site in central Henan province, around 730km south of Beijing.
Now known as the Assyrian Church of the East, the Nestorian Church is believed to be the earliest movement to spread the Gospel across China. It was regarded by the Vatican as schismatic but in 1994, the two Churches signed a common declaration of doctrine.
The discovery of the site, which features a niche in a stone wall with a cross carved above it, was made in 2009.
Precise dating is still ongoing, but historians place the period of its construction as some time during China's Ming and Tang dynasties of 316 to 907 AD.
It is not yet known whether it is older than the Nestorian Stele, an inscribed limestone tablet found in the city of Xi'an, which dates back to 781 AD. The Stele is considered to be the oldest surviving Nestorian artefact.
The discovery of the Henan site was made by Jiao Jianhui, a researcher at the Longmen Grottoes Research Institute.
The grottoes contain thousands of Buddhist and Daoist works of art carved into the stone. But speaking to UCANews.com, Jiao said: "This is the first discovery of a religious relic other than that of Buddhism and Daoism."
Recalling the moment when he discovered the site by chance, Mr Jianhui said. "I felt instantly that it was different from other niches and grottoes.
"There are many similar niches at the grottoes, carved with Buddha statues as well as inscriptions to say that the deceased are buried there. So it is certain that the Nestorian site was also for burials."
Originating in the Middle East in the fifth century AD, the Nestorian Christian Church initially received Tang Emperor Taizong's official recognition and blessing, but it was later suppressed by his successors.
The discovery of this grotto sheds new light on relations between the faiths in this period.
"Historical records shows Buddhist suppression of the Nestorian Church in the Tang Dynasty," said Jiao.
"But the niche shows some religious tolerance, as the two religions could coexist harmoniously at the Grottoes."