Melbourne, Oct 3 A new survey has revealed that more than three quarters of energy drinks sold in New South Wales, which are easily available to children, contain illegal levels of caffeine.

When NSW Food Authority tested 70 such energy drinks, they found that 77 percent had dangerously high levels of caffeine, with some breaking the law by 30 per cent.

The tests, ordered by Primary Industries Minister Ian Macdonald, came amid revelations that children had suffered serious side effects, including dizziness, nausea and heart palpitations, after consuming "shots" of a high-caffeine energy drink on the way to school.

It was reported that year 7 students, who bought 60ml bottles of one drink from a service station, had to be treated in the school sick bay before being sent home.

Macdonald threatened to seize the worst products and warned suppliers they faced prosecution.

"I am concerned by the anecdotal reports of young people being adversely affected by these products," the Daily Telegraph quoted him as saying.

"The Government is taking immediate action on this matter. I have asked the NSW Food Authority to contact all those manufacturers and/or distributors to ensure their drinks comply with the legal limits for caffeine," he stated.

Five of the eight drinks exceeding the legal limit by more than 30 per cent have already been taken off the shelves, including Fuel Cell and Cintron varieties.

Those still on the shelves are Red Eye Platinum and Smart Energy Blood Orange and Chilli and Citrus.

The State Government has moved to stop energy drinks being classed as a medicine or a dietary supplement.

"The Food Authority will do further testing of energy drinks," Macdonald added. (ANI)