Two men were in a critical condition at the Mid-Western Regional Hospital in Limerick last night following a party on the south side of the city.
Five men, all members of the same family, were taken to hospital after the party on Sunday night.
The men, in their 20s, are believed to have taken a cocktail of illicit drugs including cocaine. A large amount of alcohol was also consumed.
It is understood that all five were admitted to hospital early on Monday morning. Two remained in a critical condition last night at the intensive care unit of the hospital.
The three other men were discharged after treatment.
“A large cocktail of drugs, including cocaine and tablets that are available on the black market, were consumed,” said a Garda source.
“It was a big party and there was also a large amount of alcohol consumed and it was a combination of both the alcohol and the drugs that led to the the problems,” he added.
Gardaí have launched an investigation to establish the source of the drugs. It is understood a small amount of drugs have been seized as part of the investigation.
Officers have conducted searches of a number of locations across Limerick where it is suspected the drugs may have been sourced.
Gardaí at Roxboro Garda station are leading the investigation.