A Chinese local government official has killed himself a week after a landslide from a pile-up of construction waste in his city left scores missing and presumed dead.

Shenzhen Police said the head of the Urban Management Bureau in the city's Guangming New District jumped to his death from a building on Sunday.

The official was identified only by his surname, Xu. No further details were given.

In the December 20 disaster, a mountain of construction waste collapsed amid heavy rains onto an industrial park in Guangming New District, killing one person and leaving 75 missing and presumed dead.

In a rare move, Shenzhen's senior officials, including the city's Communist Party chief and its mayor, bowed deeply at a news conference to apologise.

It was not clear if Xu was under investigation over the landslide, although the responsibilities of the Urban Management Bureau usually include regulating businesses and construction sites.

Officials have labelled the landslide a man-made disaster, raising the possibility of harsh penalties for those held responsible.

Also on Sunday, the owner of a gypsum mine in the eastern province of Shandong, Ma Congbo, drowned after jumping into a well in an apparent suicide during rescue efforts for 17 workers still trapped two days after the mine collapsed and killed one person.

Despite the threat of prison time over major industrial accidents, a lack of regulatory oversight and cost-cutting by management often lead to disasters.