Four revellers fighting for life after nine people rushed to hospital in 'mass overdose on a dodgy batch of pills' at Australia Day festival

Emergency response after nine people fell critically ill in Melbourne. File photo / AAP

Four revellers continue to fight for life in hospital after nine people overdosed on an illicit drug at a dance party in Melbourne.

Emergency crews rushed to the "I am Hardstyle" event at Festival Hall on Friday night after reports a group of young partygoers had stopped breathing.

State health commander Paul Holman said the quick response from medical teams and first responders saved lives, the Daily Mail reports.

'They had St John Ambulance there providing first aid, they had a doctor there who was providing intervention,' Mr Holman said.

'If they hadn't been there, certainly some of these young people might not even have got to the hospital.

'These people were hyperthermic so extremely hot. They can't regulate their temperatures [and] they were extremely unconscious.

'They were unrousable, they needed to be intubated and they needed to be ventilated. So they were non-breathing patients.'

The exact form of drugs taken has not been confirmed, though they are believed to be a mix of poisons similar to MDMA.

Police are now said to be testing the drugs to find the exact strain of substance taken by the revellers.

'We are extremely concerned about this particular batch circulating around the community,' Mr Holman added.

'These are not drugs, they are poison. And this is what they have done to these young people – they have poisoned them, and they may kill them.

'So the message is don't take these substance. They are going to hurt you and they are going to kill you.'

Four people have since been discharged from hospital with the youngest of the casualties aged 17, The Age reported.

Emergency services were called to Festival Hall in west Melbourne at around 11.20pm to reports several people had collapsed.

The event, supposed to be for over 18s, was already five hours in when emergency services were called with partygoers reporting the event was cut short.

A Victoria Police spokesman said: 'Police attended an event in West Melbourne . . . following reports that a number of people were allegedly drug affected and required medical attention.

'Emergency services were called to the Dudley Street venue about 11.20pm. Nine people were conveyed to hospital in a serious condition.'

A spokesman for Ambulance Victoria said earlier; 'Emergency services were called to the dance party at 11pm. Paramedics treated eight people in a St John Ambulance first aid area at the venue.

'A ninth person collapsed nearby and was treated. All nine were taken to hospitals including Royal Melbourne Hospital, St Vincent's Hospital, The Alfred and Western Hospital Footscray in a serious condition.'

The Festival Hall, which recently announced it is due to close, is capable of holding around 5000 people.

The venue was packed for the event, which kicked off at 6pm and featured six world-famous DJs and international artists with tickets costing up to $120.

The Festival Hall has been approached for comment by Daily Mail Australia.