ZHENGZHOU, April 24 (Xinhua) -- The drug supervision bureau of Zhengzhou, the capital of central China's Henan province, is working with local police to investigate allegations of medicine capsule dumping following a scandal involving the use of contaminated medicine capsules.

The bureau and local police are investigating the dumping of a large quantity of medical capsules into a roadside drainage ditch in the city's Zhongyuan district. The capsules have polluted a section of the ditch measuring about 300 meters in length.

Local residents said the capsules were dumped discreetly several days ago, adding that they had no knowledge of any nearby medicine or capsule manufacturing plants.

The dumping came after a media report revealed that some Chinese manufacturers have packaged several types of medication in capsules made of toxic industrial gelatin.

China Central Television (CCTV) reported on April 15 that 13 commonly prescribed drugs had been packed into capsules made from industrial gelatin fake oakleys, which contains a much greater amount of chromium than edible gelatin.

Chromium can be toxic and carcinogenic if ingested in large amounts.

The Ministry of Public Security said on Sunday that it has confiscated 77 million capsules made with chromium-contained industrial gelatin.

The ministry also arrested nine suspects, detained 54 others and shut down 80 illegal capsule manufacturing lines.