Gardaí in Dublin are appealing for a taxi driver to come forward with information.
The driver in question picked up two men, one of whom was injured, from the Sundrive Road area of the city and brought them to St James's Hospital sometime after 3.15am last Sunday morning.
The injured man had been shot.
Gardaí believe the taxi to be a Volkswagen Passat or Silver Toyota Avensis.
Anyone with information is asked to contact gardaí at Sundrive Road Garda Station on 01-6666600.