Hundreds of people became ill after drinking Coca-Cola products in France and Belgium during May and June.

A report into the contamination incident by the European Commission's consumer protection department says it is "not entirely satisfied" with the company's explanation of the source of the problem.

Coca-Cola is the world's top selling soft drink

It also criticised the French and Belgian authorities reaction to the scare.

The investigators said Coca-Cola's claim that fungicide used on pallets at its plant in Dunkirk, France, was partly responsible was "highly unlikely".

The report called for the judicial and administrative investigations in France and Belgium into the contamination incident to continue.

"It is essential to find out the real cause of the contamination," it said.

In June, Coca-Cola withdrew millions of cans and bottles of soft drinks from some European markets after consumers reported suffering headaches, nausea, abdominal pains, vomiting and diarrheoa.

The company said the contamination had been caused by poor-quality carbon dioxide being used to add fizz at its Antwerp plant, in Belgium, and fungicide in pallets used for shipping the products from Dunkirk.

Overconfidence

The EU report said the carbon dioxide explanation "may be credible", but that it was very unlikely that both explanations could be true, as the two different forms of contamination would not produce the same symptoms.

The report said that one possible explanation may be that mistakes were made in the selection of plants used for the extracts in Coca-Cola's drinks, or in the amount of extract used.

Analysis had revealed an abnormally high level of aromatic essence in samples of suspect drinks, the EU investigators said.

French and Belgian authorities were criticised for showing too much confidence in the risk control measures implemented by Coca-Cola.

The report said that while the authorities' reaction had been quick, a French regulation ordering the withdrawal of some batches of Coca-Cola drinks did not work in practice.

Belgian checks on the withdrawal of contaminated products were inadequate, the report concluded.

Troubled times

Commenting on the Commission report, Coca-Cola spokesman Paul Pendergrass said: "We've worked very hard to co-operate with all the relevant authorities in providing detailed information and the facts behind the incidents."

The contamination scare hit sales of Coca-Cola products in Europe in May and June, and the EU report comes at a troubled time for the European wing of the global drinks giant.

European anti-trust regulators last month raided Coco-Cola bottlers in Germany, Austria, Denmark and the UK after allegations that the company was using its financial muscle to gain unfair trading advantages over its rivals.