Two Chinese construction workers have landed in a great deal of hot water after using an excavator to dig a shortcut through the historic Great Wall.

The Youyu County Public Security Bureau said the duo, a 38-year-old man and a 55-year-old woman, had been detained as investigations into the damage continued.

The pair were working near the affected area, the 32nd Great Wall, in China’s central Shanxi province.

Authorities say they wanted to reduce the distance they had to travel with the digger to get to their worksite. So they are accused of using it to enlarge an already existing gap in the Great Wall to allow the excavator to pass through.

In doing so, the pair caused “irreversible damage” to that section of the wall, which dates back to the Ming Dynasty, local police said.

“Currently, the two suspects have been criminally detained in accordance with the law, and the case is continuing to be investigated,” state-run CCTV said.

The Ming Dynasty lasted from 1368 to 1644 but some portions of the Great Wall are more than 2000 years old.

The structure is categorised as a historical and cultural site and protected at provincial level in China. It has been a Unesco world heritage site since 1987 and is one of China’s most iconic sites.

Local police learned of the “irreversible damage” only on August 24, when they received reports of a large gap in the wall.

After patrolling the area, they eventually found the man and a woman in a neighbouring county – along with the excavator.

Their names have not been released, though police said the man’s surname was Zheng and the woman’s was Wang. Both are from Horinger county in the Inner Mongolia Autonomous Region of China.

The pair have admitted using the excavator to make it easier for them to pass through the wall. They have been charged with destroying a cultural relic.

There is now a broad gap in the historic wall. Photo: Youyu County Public Security Bureau

The 20,000-kilometre-long Great Wall was built and rebuilt continually from about 220BC until the Ming Dynasty in the 1600s, when it was the world’s largest military structure.

Better-known parts of it showcase beautifully built structures dotted with ancient watchtowers, but other parts – particularly in rural areas – are crumbling or have disappeared altogether.

In 2016, the Beijing Times newspaper reported that more than 30 per cent of the Ming Great Wall had disappeared entirely, with only 8 per cent of it considered well-preserved.

-with agencies