Gardaí have appealed for information concerning the death of a man in Dublin last February. 

48-year-old John Hannigan was discovered in the hallway of his apartment complex at Grosvenor Road in Rathmines on 3 January. 

He was taken to St James' Hospital where he later died. 

Gardaí say that a post-mortem was conducted, but the results are not being released for "operational reasons".

An investigation established that at 1.30pm on 3 January, John travelled to Balally, Sandyford in Dublin where he briefly met a family member.

However, there is no detail on his movements after he left the area up to when he was discovered at his apartment complex at 6pm on the same day. 

The sole cause of death has yet to be established and gardaí say they are investigating "all the circumstances of this unexplained death". 

Gardaí are appealing for anyone with information to come forward. 

They are particularly interested in information on John's movements from the New Year period to 3 January. 

Anyone with information is asked to contact Rathmines Garda Station on 01 666 6700 or the Garda Confidential Line on 1800 666 111. 

This case will be featured on tonight's episode of Crimecall on RTÉ 1.