Five edible oil companies operating in South Africa, including Singapore-based agri-food giant Wilmar International, have been raided as competition officials investigate claims of price-fixing.

South Africa's Competition Commission today (8 December) visited the offices of Wilmar Continental Edible Oils and Fats, Willowton Oil and Cake Mills, FR Waring Holdings, Africa Sun Oil Refineries and Epic Foods, all companies suspected of engaging in a cartel, which, the regulator said, started in 2007 and is still ongoing.

The companies are accused of fixing prices for "refined edible oils including baking fats and margarine", the Competition Commission said.

Tembinkosi Bonakele, the Competition Commission commissioner, said: "Food and agro-processing is an important focus area for the Competition Commission, and we are determined to root out exploitation of consumers by cartels that are so prevalent in this sector. We have, in particular, been monitoring developments in the fats and oils markets and what we see is worrisome."

In a statement, Wilmar International said: "Wilmar is disappointed by today's unfortunate events but cannot comment further on any matters which are part of the ongoing investigation. Wilmar takes legal compliance very seriously and adheres strictly to the principle of complying with all applicable laws, rules and regulations in the countries in which it operates. Wilmar is cooperating with all parties involved to gather information in order to assist with the investigation."

Willowton Oil and Cake Mills, FR Waring Holdings, Africa Sun Oil Refineries and Epic Foods could not be reached for immediate comment.