A man in his 30's is being questioned in connection with the death of an elderly woman in Carrigaline.
The woman in her 80's died yesterday after receiving treatment for a head injury.
The elderly woman was transferred to Cork University Hospital after a suspected assault at her house in Kilmoney.
She died in CUH and a post mortem is due to be carried out on her body today.
The house in Carrigaline has been sealed off for a technical examination.
A man in his 30's is being questioned at a Garda station where he can be held for up to 24 hours.