A Chinese baby born with a cleft lip was abandoned by his parents and buried in a cardboard box two days later, but rescued alive eight days further on, media reported.

The parents left the baby in a remote countryside in the southern province of Guangxi, before he was buried, apparently by relatives who believed he had died, Guangxi Online News said.

But water and air were able to seep into the box, the report said.

The baby was buried in a container the size of a shoebox on a dusty dry, landscape, surrounded by long grass, according to images posted by China Central Television on its verified account on Sina Weibo, China's version of Twitter.

He was discovered when a woman heard him crying as she was picking herbs, the post by the state broadcaster late Tuesday said.

The baby was spitting soil when doctors examined him last week, the Guangxi Online News said.

"Five people including three relatives have been detained on suspicion of intentional murder," CCTV said.

A disabled child can be a huge drain on a family's resources in China, and many of the babies abandoned in the country are given up because parents cannot afford expensive medical bills and fees for special education, authorities say.

China's strict family planning rules can also be a factor, although the one-child policy normally allows parents to have another baby if their first is disabled.

A relaxation of the regulations in late 2013 also allows couples to have two offspring if at least one parent was an only child.