A 22-year-old man is dead and two others are in hospital after taking an 'unknown substance' at the Lost Paradise Music Festival on the NSW Central Coast on 29 December.
NSW Police said some people have tried to smuggle drugs into the event through so-called "sophisticated" methods, including compartments within Vegemite jars and inside the stuffing of a barbecue chicken.
More than 180 people and 97 vehicles have been searched during the festival's police operation, while three people have been charged with drug supply offences.