Gardaí have released a man arrested yesterday in connection with the murder of Joseph Rafferty in Dublin last month.
The man was released without charge and a file was sent to the DPP.
Five other men who were arrested yesterday are still in custody.
Mr Rafferty was shot twice in the upper body as he was leaving his apartment at Delhurst Terrace in the Hayward apartment complex in Ongar Park, halfway between Clonsilla and Clonee, Co Meath.
He was originally from the south inner city but had been living at the west Dublin apartment with another man for about a year. He had a number of convictions for road traffic offences and was believed to have been involved in the hijacking of a lorry about eight years ago.
Gardaí believe he was shot by one gunman, who fled on foot after the attack.
The gunman struck as Mr Rafferty was about to get into his UK-registered white Mercedes van and make his way to the city centre where he worked as a courier.