A teenager has died following a suspected drug overdose at a dance party in Sydney on Saturday night.

More than 18,000 people attended the dance party. Police officers at the festival issued 69 banning notices and conducted more than 200 searches, with 62 people found in possession of drugs.

Asked if it was time to reconsider the government's position on pill testing,Premier Gladys Berejiklian said pill testing won't work because it'll give people a green light to taking substances, which in the end could still kill them.