Dance party shut down after drug overdoses

A dance party in Sydney was shut down by police after four revellers were believed to have overdosed on the drug GHB.

Officers with sniffer dogs were at the Genesis Black Subculture trance music event that kicked off at 7pm on Sunday night at Hordern Pavilion in Moore Park.

They were concerned about the number of people affected by drugs and evidence of drug supply.

Four people were also treated for suspected drug overdoses and taken to St Vincent's Hospital, police say.

Police returned to the venue at 2am on Monday morning to issue a shot-term closure order to the promoter and licensee.

The party's organisers, Genesis Events, suggested attendees affected by drugs were safe.

"Hi Sydney, everyone is safe!" the group said on Facebook.

"We are as disappointed as you are with the early end to tonight's event but hope you can understand that it was out of our control!"

A hospital spokesman said the patients had been discharged in a satisfactory condition on Monday morning after being treated for suspected overdoses on party drug GHB.