The Health Information and Quality Authority has deferred publication of the report into the care that breast cancer sufferer Rebecca O'Malley received after she was initially misdiagnosed.
The report is now expected to be available next month.
Dr Michael Durkin, who is heading the investigation team, said that new information had been brought to the attention of the Authority in the last few days and it needs further investigation.
In March 2005 the 41-year-old underwent a biopsy at the Mid-Western Regional Hospital in Limerick to test for suspected breast cancer.
Due to an excess workload in the hospital the sample was sent to Cork University Hospital. The Tipperary mother-of-three was given the all clear.
However, 14 months later in 2006 a second test revealed she had invasive breast cancer and she underwent an immediate mastectomy.
In May this year a HSE report concluded the misdiagnosis was a result of an interpretative error.
Unhappy with the findings, Rebecca O'Malley insisted the Minister for Health establish a full and independent inquiry.
Mary Harney agreed to that request and the inquiry was undertaken by the recently-established Health Information and Quality Authority.
