Gardaí have released three men without charge in connection with a fatal shooting and aggravated burglary in Co Louth last Friday
A file is being prepared for the Director of Public Prosecutions.
Stephen Hanaphy (20), Cromcastle, Coolock, north Dublin, was fatally wounded in the incident just after 11pm last Friday. His body was not found until nearly six hours later on a green area on the Sliabh Breagh estate in Ardee.
A man (30) was arrested in the Ardee area of Louth earlier this morning and two other men aged 21 and 55 were arrested on Monday.
Another man (26), who was arrested in Dublin yesterday, was released pending further investigation, gardai said.
Detectives are investigating whether the shooting dead of a man and the wounding of a second at a house in Co Louth arose from a planned debt collection beating or a kidnapping that went wrong.
A second man presented himself to Beaumont Hospital, north Dublin, for treatment for gunshot wounds following the incident on Saturday. He underwent surgery for wounds to his arm and shoulder and is expected to make a full recovery.
Gardaí believe the wounded man and Mr Hanaphy were part of a four-man group that travelled by car from Dublin to the Sliabh Breagh estate on Friday night to carry out an attack.
Detectives believe the gang may have been paid by another party who wanted the younger of two men in the Ardee house either beaten or kidnapped, possibly to force payment of a drugs debt.
An effort was made to attack the man in Ardee last Wednesday but he managed to escape.
One of the gang that went to the Ardee house is a known debt-collector also involved in “settling rows” between Travellers.
The two men living in the house targeted in the Sliabh Breagh estate are Travellers. The father and son from Dundalk have been living in Ardee for 12 months.
Gardaí believe Mr Hanaphy, a body builder, may have been brought along to Ardee as “muscle”. He was not a gangland criminal.