Six people arrested over the dissident republican murders of two soldiers and a police officer today won a legal challenge against their continuing detention.
Four suspects in the soldier murders — including prominent republican Colin Duffy — were released.
A PSNI spokeswoman said: “This remains a live and active major investigation and detectives are following a number of definite lines of inquiry.”
The released men were among those who successfully contested a seven-day extension to their detention period, granted to police by a County Court judge. In a ruling that may have implications for UK anti-terror laws which provide for 28-day detention, that decision was quashed today in a High Court ruling delivered by Lord Chief Justice Sir Brian Kerr.
It concluded that the County Court judge had been wrong in not examining the lawfulness of the original arrests.
The High Court hearing had been told that the police were holding suspects while awaiting the outcome of forensic tests.
Four of those in custody, including Duffy, had been questioned about the Real IRA murders of Sappers Mark Quinsey (23) from Birmingham and 21-year-old Londoner Patrick Azimkar outside Massereene Army Barracks in Antrim on March 7.
The other two have been held in connection with the murder of PSNI Constable Stephen Carroll by the Continuity IRA in Craigavon two days later.
None of the suspects were in court today for the ruling. All of them, aside from Duffy have been granted anonymity in the case.
The decision to quash the County Court’s detention extension order was made by a three-judge panel, headed by the Lord Chief Justice.
Sir Brian today stated that while the lawfulness of the arrests had to be examined, this did not have to include detailed analysis of the police’s grounds. It was accepted that disclosure of the full information would not be necessary, “for reasons of public safety”.
A solicitor representing one of those being questioned over the murder of Constable Carroll said today he now expected his client to be released from custody.
Joe McVeigh, of Kevin R Winters solicitors, was in the court to hear today's ruling.
Mr Mc Veigh said: “The decision of the court has backed the position that the defence lawyers have taken from the very start of the arrests,” he said after the ruling.
“We have always taken the view that not to examine the conduct of arresting officers when considering to detain people under the Terrorism Act has always been a breach of human rights.”
Mr McVeigh said today's ruling should allow his client to return home.
He added that none of today's events could take away from the grief suffered by Pc Carroll's widow and family.
Head of the Human Rights Commission Monica McWilliams sparked controversy yesterday by criticising the conditions that the suspects were being held in in the serious crime suite of Antrim police station.
Professor McWilliams said the holding centre had been designed for detaining suspects for shorter periods than the current 28 days allowed under current legislation.
Chief Constable Sir Hugh Orde said yesterday he had visited the station and declared that he believed it was fit for purpose.
Meanwhile, a former Sinn Fein councillor appeared in court today charged with murdering Constable Carroll.
Brendan McConville (37) also denies possession of a firearm with intent to endanger life.