Searches in two towns located in the midlands are being conducted by gardaí in an attempt to locate a batch of drugs that is suspected to have caused three deaths.
The batch of drugs are believed to be fake Xanax tablets which were purchased online.
Angela Kelly (44) died at Clonamore House Hotel in Tullamore last Sunday and Amy Mannix (19) died there last Monday.
A 23-year-old man, understood to be the boyfriend of Ms Mannix, died last night at Midlands Regional Hospital.
A fourth man, aged in his 30s, was discharged from hospital.
The searches are taking place at Tullamore and Portarlington by gardaí who are being supported by the Armed Support Unit, the Garda Dog Unit and the Laois/Offaly Divisional Drugs Unit.