(Yicai) July 10 -- Chinese authorities are expanding their latest food safety investigation following a recent media exposé which claimed that firms use tankers contaminated with coal-derived chemicals to transport liquid edibles such as syrup and soybean oil.

Authorities yesterday conducted a special investigation into the transportation of vegetable oil at a Dongguan-based grain and oil affiliate of COFCO Group, the state-owned food processing giant told Yicai today.

The firm was involved in the case as one of the oil tankers mentioned in the media report loaded edible oil in Dongguan on June 1 and arrived at a factory of Yihai Kerry Arawana Holdings in Xianyang, Shaanxi province, to unload the cargo on June 4, according to public information.

Reportedly, the firm had used the same tankers both for kerosene and edible oils, resulting in contamination. One of COFCO's oil tankers loaded edible oil in Dongguan on June 1 and arrived at a factory of Yihai Kerry Arawana Holdings in Xianyang, Shaanxi province, to unload the cargo on June 4, according to public information.

Beijing News reported on July 2 that a long-term investigation has revealed that many general-purpose tankers carry both edible liquids and chemical liquids such as coal-derived oil. The probe busted China Grain Reserves, also known as SinoGrain Group, and Sanhe Hopefull Grain & Oil Group. To cut costs, the tankers are not cleaned between shipments so edible oils are contaminated with toxic chemicals, the report added.

The report sparked a strong public outcry. SinoGrain and Sanhe said they have launched large-scale internal investigations. Additionally, several other manufacturers of edible oils, including Yihai Kerry and Luhua Group, rushed to confirm they strictly adhere to safety regulations.

The government has quickly intervened as the State Council has organized a joint investigation team comprising multiple government departments, including the Ministry of Public Security and the Ministry of Transport, to conduct a thorough investigation into issues related to the transportation of edible oils, Xinhua News Agency reported yesterday.

Editors: Dou Shicong, Emmi Laine