Detectives investigating the murder of Colin Horner in a Bangor supermarket car park have arrested a 45-year-old man in the Newtownards area.
The news comes as a 28-year-old man is due to appear in Newtownards Magistrates Court charged with the murder.
He also faces charges of possessing a firearm and ammunition with intent to endanger life.
Colin Horner, 35, was shot dead in front of his three-year-old son and crowds of shoppers outside a branch of Sainsbury’s in the Balloo Link area of the Co Down town on Sunday afternoon.
The victim is believed to have been killed after moving to Bangor from Carrickfergus amid fears he would be targeted as part of an ongoing loyalist feud.
Mr Horner was an associate of George Gilmore who was shot dead in Carrick in March.