Following through on an earlier threat, the Center for Science in the Public Interest (CSPI) is asking the courts to prohibit MillerCoors Brewing Co. from selling its Sparks energy drink, the Associated Press reported Sept. 8.

Earlier this year, CSPI threatened to sue both MillerCoors and Anheuser-Busch over the sales of alcoholic energy drinks, which the advocacy group contends appeal to underage drinkers and contain unapproved additives like guarana and caffeine. Anheuser-Busch subsequently decided to stop selling the drinks, but MillerCoors continued to sell Sparks, prompting CSPI to file suit in Superior Court in the District of Columbia.

The industry watchdog contends that including caffeine, guarana, ginseng or taurine -- common ingredients in energy drinks -- in alcoholic beverages is illegal. A group of state attorneys general and the U.S. Alcohol and Tobacco Tax and Trade Bureau are investigating whether alcoholic energy drinks are being marketed for their alleged health benefits, which would be illegal.