The fatal shooting of a man in front of his three-year-old son was part of an ongoing feud amongst loyalist paramilitaries, a court has heard.
Murder suspect Ryan Graham Smyth, 29, was refused bail by a district judge after police warned that if he was released from custody it could "feed into tensions".
Smyth, from Windsor Gardens in Bangor, County Down, appeared before Downpatrick Magistrates' Court on Monday charged with the murder of 35-year-old Colin Horner on Sunday May 28.
He was also charged with possession of a firearm with intent to endanger life.
Mr Horner was shot outside a supermarket in Bangor, County Down, in front of his son.
Smyth, who was handcuffed in the dock, only spoke to say he understood the charges against him.
A number of friends and family smiled at him from the public gallery.
Several armed police officers lined the courtroom during his short hearing.
A PSNI detective told the court that police believe Mr Horner's murder was "part of ongoing mounting tensions within South East Antrim UDA".
He claimed it was connected to the murder of ex-UDA chief George Gilmore in Carrickfergus in March.
The detective sergeant said he was concerned that if Smyth was released on bail it could feed into tensions and there was a prospect of further offences being committed.
He told the court that the gun used in the attack has not yet been found, and if released from custody Smyth could "obstruct" officers from locating the weapon.
He also said he was concerned Smyth would interfere with witnesses.
"This is a very serious offence and police strongly object to bail.
"Police believe (the defendant) has strong links with the UDA," he added.
A defence lawyer told the court that Smyth had a limited record of driving offences and there was nothing to suggest he posed a risk to witnesses.
The lawyer added: "There is no evidence to cause the court to conclude that Mr Smyth poses a risk of further offences or interference of witness."
However, the district judge said that in the context of an ongoing paramilitary feud she was not prepared to grant bail.
Smyth was remanded in custody to appear before Newtownards Magistrates' Court via video link on June 30.
A second man charged in connection with the murder was recently released on High Court bail.