Dublin City Coroner's Court has referred the death of Brian Murphy almost seven years ago back to the Director of Public Prosecutions.
The teenager died during a fight outside Anabel's nightclub in south Dublin in August 2000.
A preliminary hearing ahead of the inquest into his death was held today to examine three medical reports from the State Pathologist, her predecessor and a pathologist representing the Murphy family.
In his original report, former State Pathologist Dr John Harbison said the death was due to head injuries, but his successor, Dr Marie Cassidy, later said she believed alcohol may have contributed to the death.
In evidence today, she said she now accepted that head injuries were the case of death, but said a question mark still remained over the mechanisms leading to Mr Murphy's death.
The coroner subsequently decided to refer the matter back to the DPP.