A man who was in a critical condition after becoming unresponsive at a homeless hostel in Co Offaly earlier in the week has died.
The 23-year-old man had been receiving medical attention at the Midland Regional Hospital in Tullamore since Monday.
Two women died at the same hostel on Sunday and Monday.
Another man, aged 32, was also taken to the hospital and has now been released.
Earlier in the week, Gardai said they were investigating whether a batch of counterfeit Xanax tablets, purchased online, had led to the deaths.
Gardai are carrying out searches in Tullamore and Portarlington on Friday morning.
Armed gardai, the Garda Dog Unit and the local Drugs Unit are assisting the searches.