Lawyers and a consumer advocacy group are suing The Coca-Cola Co for deceptive marketing of its VitaminWater drink, a claim derided as "ludicrous" by the soft drinks giant.

VitaminWater is marketed as a healthy alternative but each bottle contains 33g of sugar, which may raise the risk of obesity and associated health problems, such as diabetes, allege the complainants.

A lawsuit has been filed in California by law groups Whatley Drake & Kallas LLC and Reese Richman LLP, in co-ordination with the Center for Science in the Public Interest (CSPI), the groups said today (15 January).

Patrick Sheehan, lawyer for Whatley Drake & Kallas, accused Coca-Cola of "deliberately deceiving" consumers.

"This is a ridiculous and ludicrous lawsuit," said a Coca-Cola spokesperson today, accusing the CSPI of "grandstanding" in order to gain publicity.

She added: "Consumers can readily see the nutrition facts panels on every bottle of glacéau vitaminwater, which show what's in our product and what's not. The success of glacéau vitaminwater is due in large part to consumers looking for a product like this to help support their healthy, active and on-the-go lifestyle."

The lawsuit follows a warning to Coca-Cola from the US Food and Drug Administration (FDA) in December, regarding the firm's Diet Coke Plus drink, which contains added vitamins.

FDA has told Coca-Cola to change its the product's name and said that adding functional ingredients to carbonated soft drinks was "not appropriate". Coca-Cola has disputed the FDA's findings.