Nearly 25,000 people attended the day-long festival at the Sydney International Rowing Centre.

The police crackdown followed the death of a 26-year-old man at last year's festival. In 2013, a 23-year-old man died after overdosing on ecstasy.

The police operation is the latest attempt to stem the growing use of ice. Officers from Penrith Local Area Command, the North West Metropolitan Region and the Dog Squad monitored the behaviour of festival goers throughout the day.

They targeted drug and alcohol offences, anti-social behaviour and public safety.

During the operation police conducted a number of person searches.

There were 77 drug detections.

Six people have been charged with supplying a prohibited drug

More than 200 people received medical treatment for drug and heat-related illnesses with six taken to Nepean Hospital for further treatment.

Police also conducted 630 random breath tests and charged eight people with drink driving. Another 44 people returned positive results for driving under the influence of drugs.

Defqon.1  is an annual music festival that has been held in Australia, Holland and Chile since 2003.