Three men are in a stable condition in hospital after falling ill while undergoing a clinical trial for a drug at a Cork clinic.

They were taken to Cork University Hospital when they took ill at a trial at the private Shandon Clinic this morning.

Three HSE ambulances, two rapid response vehicles and two advance paramedics responded to the call.

12 healthy male volunteers, with no previous medical problems, were involved in the testing, which is the latest in a series for the drug being conducted at the Shandon Clinic.

The trial had been due to run until next Thursday, but has now been terminated.

The remaining volunteers will stay at the clinic under medical supervision as a precaution.

The Irish Medicines Board has commenced a full investigation into the trial.

Shandon Clinic has also informed the Clinical Research Ethics Committee of the Cork Teaching Hospitals.

The trial was to determine the bioavailability of a drug for its potential use in the treatment of cancer.