A man who was found with head and face injuries at a house in the Grafton Street area of Derry has died.
Detectives have now issued a further appeal for information.
Police received a report shortly after 6:35am on Tuesday morning that a 43 year old man had been hospitalised on Monday for treatment to his injuries.
Yesterday he was described as being in a critical but stable case.
Police say a post mortem examination will now take place to establish the cause of death.
Anyone who has information which may assist the investigation is again being urged to contact detectives at Strand Road.