BEIJING - Procuratorial organs in Northern China's Shanxi province have been urged to "strictly" investigate the chemical leak scandal by a local company 11 days ago, according to the Supreme People's Procuratorate (SPP).

In a circular Wednesday, the SPP ordered serious investigation into the December 31 leak of about 9 tonnes of aniline into a river in Changzhi City by Tianji Coal Chemical Industry Group, Xinhua was told Thursday.

Environmental workers pour water treatment material into the Zhanghe river to purify the water in Yuecheng reservoir in the downstream city Handan, North China's Hebei province on Jan 8, 2013. Nearly nine tons of aniline, a toxic chemical widely used to manufacture pigments, leaked from a chemical plant in North China's Shanxi province, affecting the city's water supply in neighboring Hebei province. The treatment involves pouring activated carbon - charcoal that has been treated with oxygen to open up millions of tiny pores between the carbon atoms – into the water system. [Photo/Xinhua]

The SPP has sent a special work group to Shanxi to supervise and direct the investigation.

Government employees whose acts in the accident constitute a crime of dereliction of duty will be handled in accordance with laws, according to the circular.

The contamination caused by the leak affected drinking water supplies of the Yuecheng Reservoir in downstream Handan, Hebei Province. The leak also polluted a river in neighboring Henan Province.

Changzhi City authorities were also found to have delayed reporting the leak until six days later.