50 Cent arriving at Salt Lake City airport for the 2009 Sundance Film Festival, Salt Lake City, Utah - 16.01.09

The In Da Club hitmaker sells his Formula 50 drink through the Coca-Cola-owned brand.

But Vitaminwater's reputation has come under threat after officials at The Center for Science in the Public Interest (CSPI) filed a class action suit against its parent firm, claiming executives knowingly misinformed customers about the benefits of the drink.

The lawsuit alleges "buzzwords" like "defence", "rescue" and "energy" were used to market the health-concious product when it really should have warned about the "sugar" levels in the drink.

CPSI spokesman Steven Gardner says, "It is really shocking that a company like Coca-Cola feels the need to market a soft drink as a vitamin pill to hide the fact it is really sugar water."

Coca-Cola bosses have denied the claims, dismissing the suit as a publicity stunt.

Source: WENN