Red Bull has become embroiled in a legal spat in the US, according to local reports.

The Austrian energy drinks producer and rival US group Vital Pharmaceuticals have launched a series of lawsuits, accusing each other of false advertising and trademark infringement.

According to a report in the Miami Herald yesterday (14 September), a US District Court has granted Vital the right to pursue the false advertising claims against Red Bull. Vital's latest legal action came after the two companies tried unsuccessfully to settle the dispute out of court.

The dispute began last October, the Miami Herald reported, when Red Bull's lawyers sent a letter to Vital demanding it pulled its Redline product amid claims its packaging was too similar to Red Bull. Vital promptly filed a suit in Miami seeking a judgement that it was not infringing Red Bull's trademark.

In March, the newspaper said, Red Bull accused Vital of false advertising with its claims that Redline has fat-burning properties. On its website, Vital espouses a "scientific breakthrough" with its Redline product, claiming it burns fat through a "shivering response", similar to when someone shivers when they are cold.

Vital hit back and threatened to file its own false advertising claims against Red Bull, a suit it was allowed to pursue last week.

Officials at Red Bull in Austria and California could not be reached for comment as just-drinks went to press. Vital representatives were also unavailable for comment.