NSW police have arrested and charged 85 people with drug-related offences at Field Day music festival in Sydney.

Sniffer dogs helped police detect and seize MDMA, ketamine, psilocin (mushrooms), LSD, cocaine and cannabis. More than 80 people were arrested for drug possession and two for supply.

Almost 12,000 people attended the annual New Year’s Day festival at The Domain in the city’s centre to watch electronic duo Peking Duk, DJ Anna Lunoe and Brisbane singer Mallrat among others.

One of the drug supply charges was of a 22-year-old man allegedly found with 50 capsules of MDMA.

Police allege the man “struggled with police” during the search causing a senior constable minor injuries.

The man was then arrested and charged with supplying a prohibited drug, assaulting police and resisting arrest.

He was refused bail to face Parramatta Local Court on Sunday.

-AAP