Gardaí say they have made good progress in their investigation into the supply of ecstasy which has left a teenager in a critical condition after becoming ill at a music festival in Co Cork.

The 19 year old from the Clonmel area of south Tipperary was with friends at the Indiependence festival in Mitchelstown in north Cork when he started to feel unwell at around 4.30pm on Friday.

He was rushed to Cork University Hospital by ambulance after being brought to the festival’s medical tent by friends.

The teenager, whom it’s understood completed his Leaving Cert earlier this summer, remains in a critical condition in the Intensive Care Unit at CUH where his parents are maintaining a bedside vigil.

Meanwhile gardaí have begun an investigation into how he became ill and have established that he ingested what he believed was MDMA or ecstasy about a hour beforehand.

Gardaí believe that the substance was a particularly potent form of the drug and while they have established that others also took it, they did not have the same reaction.

Officers have spoken to others at the festival who took the drug in an attempt to identify its source , and although they have yet to make any arrests, they say they have made good progress.

Word of the young man taking ill spread quickly at the festival on Friday evening and the organizers issued an immediate warning to all festival goers not to take any unknown substances.

“Welfare Message – We have reports of a bad batch of something in the campsite, do not consume any substances that you are unsure about, it has the potential to make you very sick,” they tweeted.

Both gardaí and festival organisers say that they are only aware of one person taking ill at Indiependence and being transferred to CUH since the three day festival began on Friday.

“A 19-year-old male reported to medical (staff) on Friday evening and was treated on site by a doctor before being transferred to CUH where his condition is being monitored,” said an Indiependence spokesman.

“To clarify media reports of drug-related issues at Indie 2019, we wish to confirm that since the event opened at 10am on Friday (August 2), we have had one drug-related transfer to CUH.

“Chief Medical Officer William Wade has confirmed that on Friday evening a 19-year-old male was transferred to CUH having received treatment from the on-site doctor.”

CUH initially tweeted that a number of patients had presented from Indiependence with drug-related issues but later updated this to clarify that only one patient was brought from the festival.

“Update on previous alert. Single patient with severe illness. Hospital has been in contact with festival organisers and medical team on site @Indie_pendence. NO NEW PRESENTATION. Reassuring to all.”

Some 15,000 music fans are attending the three-day festival which this year is being headlined by English band Bastille and Scottish singer songwriter Lewis Capaldi.