Three people have been detained by police in Shandong province in a case in which one man was killed and nine other people were made ill by parcels contaminated by toxic chemicals.

Police in Guangrao county confirmed on Monday that the head of a chemical plant in Hubei province, the head of a medicine company and the head of a branch of an express delivery company in Shandong province had been detained.

Media reported last week that Liu Xingliang died in Shandong on Nov 29 after receiving a pair of shoes delivered by YTO Express Co.

Nine others, two of whom were Liu's family members, five deliverymen and two other recipients, were sickened by contaminated parcels delivered by the same company.

An investigation found that 154 parcels in a vehicle were contaminated by a parcel containing toxic chemicals from Hubei province, the Shandong Postal Bureau said.