The 57 year old is suing for damages over the handling of the investigation into the murder of French film producer Sophie Toscan du Plantier in West Cork
A jury is due to be sworn in today for the High Court action against the garda authorities and the state.
Mr Bailey is suing for damages for alleged wrongful arrest as part of the investigation into the murder of Sophie Toscan du Plantier in Schull, in December 1996.
He was detained at Bandon Garda station on two occasions in connection with her death but he was never charged.
The case could run until Christmas with testimony expected from more than 80 witnesses including 2 former DPPs.