A comparison showing the Fanjingshan Temple on top of the Fanjing Mountain in Southwest China's Guizhou Province after the temple walls were turined into pink during a renovation Photo: Screenshot from online

Five staff from  a world heritage site in southwestern China are under investigation for painting  grey temple walls  pink without permission during a renovation.

The Fanjing Mountain, with a Fanjingshan Temple formed of two buildings on top located in Southwest China's Guizhou Province, has been famous for its geological wonders and ancient scenery which date back to over 1.4 billion years ago.

It was listed on the List of World Natural Heritages at the 42nd World Heritage Convention (listed as Fanjingshan) on July 2, 2018, the fourth World Natural Heritage site in Guizhou, following South China Karst in Libo, China Danxia in Chishui, and Yuntai Mountain (listed as Yuntaishan) in Shibing, making Guizhou the province with the most World Natural Heritage sites in China.

"As part of the world heritage, the architectural styles are not allowed to be damaged, or changed on purpose," Lü Yin, a Shanghai-based lawyer told Global Times on Sunday.

According to a regulation on the management measures of the world natural and cultural heritage application and protection published by the Chinese government in 2015, one of the articles goes as "the authenticity and integrity of the world heritage should be strictly protected and must not be changed or destroyed at will."

"This is a violation of regulations for changing the color of the wall without authorization," she added.

Three staff from the Fanjing Mountain who  oversaw the renovation have been suspended from work and a total of five who were responsible for the renovation are now under investigation.

And an expert team has been sent to restore the wall to its original look "as soon as possible," according to Southern Metropolis Daily on Sunday.

The investigation was initiated on Friday, after a video overlooking the scenery of the top of the Fanjing Mountain caught the two pink buildings inside the temple "dazzling" in the video, causing a public condemn over the management of the scenic spot.

"Regardless the purpose of this act, it is definitely not a good idea to promote themselves as such a world heritage site with such a behavior," read a comment on China's Sina Weibo.

A tourist named Cai Ziyang recalled to Global Times that he and his family went to the mountain in late June and found it under renovation at the time.

"I found it really weird but I thought it was part of the renovation process and they would turn it into the original look as grey," Cai said.

The temple was built five hundred years ago during China's Ming Dynasty (1368-1644).

The two main buildings, sitting at an altitude of 2,498 meters high, are located separately on top of two mountain tops of Fanjing Mountain which are connected by a plank road.

The ecology of the mountain is also prominent.

Fanjing Mountain is a part of the Wuling mountain range. A mainly metamorphic rock structure, the mountain is an isolated ecosystem, like an island in an ocean of Karst hills. The landform is one of a kind anywhere in the world.

This region, with its area of 775 square kilometers ranging from mid-subtropical to mid-temperate zones, is home to more than 7,000 native species.

Aiming to become a National Park, the director of Fanjingshan National Nature Reserve Administration once noted in March that the future Fanjingshan National Par" will be becoming the most strictly administrated nature reserve in the world and its ecosystems will be given higher priority.