Detectives in the North are have released a 26-year-old man they were questioning over a fatal attack nine years ago.
Paul McCauley was beaten in Derry in July 2006 but only died from his injuries last June.
He had been attending a summer barbeque in the Waterside area of the city at the time.
There have been multiple arrests over Mr McCauley's murder, but so far only one person has been charged.
A man arrested in Derry on Monday was also released on bail last night.