A researcher at a leading Australian drug education centre has backed a trial of pill testing at music festivals arguing a new wave of synthetic drugs is driving the need for the NSW government to act.

Dr Monica Barratt from the federal government-funded National Drug and Alcohol Research Centre argues such a regime would not only reduce the potential harm to users but provide data to better understand what people are taking.

NSW Deputy Premier Troy Grant has ruled out drug testing at festivals. Credit:Marina Neil

On Monday, Deputy Premier Troy Grant ruled out introducing pill testing in the wake of the latest suspected drug overdose at the Field Day festival at The Domain.

Asked if the government would consider introducing testing of drugs at festivals as is done in Europe, Mr Grant replied: "No".