The former head of the urban management bureau of Guangming New District in Shenzhen, Guangdong province, reportedly fell to his death in the city on Sunday night.

It was not immediately known whether Xu Yuan'an, 52, had been put under investigation for the Shenzhen landslide, according to Xinhua News Agency. Police have ruled out homicide.

A landslide occurred in the district on Dec 20, burying 33 buildings. Seventy-five people are still unaccounted for.

An investigation team formed by the State Council two days before the death of Xu ruled that the landslide was a safety incident rather than a natural disaster. It also determined the landslide was the result of the collapse of waste construction material used for landfill.

Caixin Media reported Xu was one of the officials who approved the construction of Hongao Construction Waste Dump, the soil storage site.

Xu had been the director of the district urban management bureau since August 2009, according to the district's personnel bureau.

No official notice has suggested when he left the post, while the current director of the bureau is Zhao Yonglin.

However, Caixin said the soil storage site was one of the key achievements of the bureau under Xu's leadership, as the bureau opened the project for bidding in 2013 and Xu was still signing contracts on behalf of the bureau in 2015.

In addition, police said on Monday they had detained 12 people involved in the landslide, including directors of Shenzhen Yixianglong Investment and Development Co.

Shenzhen LvWei Property Management won the bidding for the Hongao Construction Waste Dump in 2013 and then sold its operating service to Yixianglong for 750,000 yuan, according to the National Business Daily.