Retired police officers have failed in a High Court challenge to a watchdog report which identified RUC collusion with loyalists who murdered six Catholic men.
A judge rejected claims that the Police Ombudsman exceeded his legal powers in publishing findings on the Loughinsland massacre.
Mrs Justice Keegan said: "This is legacy case, involving the death of six people in circumstances where serious questions have been raised about police conduct.
"There is an obligation to investigate such matters and a strong public interest to know the outcome."
UVF gunmen opened fire at the Heights Bar in Loughinisland, Co Down as their victims watched a World Cup football match in June 1994.
The men killed were: Adrian Rogan (34), Malcolm Jenkinson (53), Barney Green (87), Daniel McCreanor (59), Patrick O'Hare (35), and Eamon Byrne (39).
Five others were also wounded in the atrocity for which no-one has been brought to justice.
In June 2016 the Ombudsman, Dr Michael Maguire, said collusion between some officers and the loyalists was a significant feature in the murders.
He found no evidence police had prior knowledge, but identifie "catastrophic failings" in the investigation.
Read more:Loughinisland families welcome dismissal of collusion challenge
Raymond White, representing the Northern Ireland Retired Police Officers' Association and Ronald Hawthorne, a former sub-divisional police commander, were seeking to have the report quashed.
They claim the watchdog lacks the legal power to investigate and publish damning findings without a proper chance to respond.
A first hearing resulted in a ruling last December that the report was procedurally unfair.
Another judge, Mr Justice McCloskey said it failed to make clear the findings did not apply to Mr Hawthorne.
But lawyers representing the Ombudsman and victims' families argued that he should withdraw due to his role as a barrister in separate litigation 17 years ago.
Despite rejecting claims that he could be seen as unintentionally biased, he consented to a limited re-hearing in front of Mrs Justice Keegan.
At that time the watchdog also agreed to remove any references to Mr Hawthorne from its report to ensure he is not connected to any alleged wrongdoing - a move seen as complete vindication for the former police commander.
The renewed challenge to the amended report focused only on issues around the extent of the legal powers to publish the findings.
Counsel for the retired officers stressed it was not an attack on the institution of the Ombudsman's office.
He argued, however, that damning determinations had been reached without his clients having the opportunity to respond.
The Ombudsman's legal team countered that the Police (Northern Ireland) Act gave him the required statutory power to make the determinations contained in his public statement.
Backing that position, Mrs Justice Keegan stressed it must be his function to investigate complaints.
"He also has power to refer complaints for criminal or disciplinary disposal and he can take other defined actions," she said.
"But it would be perverse to say that he cannot report on his investigation."
Dismissing the legal challenge, she noted that the Ombudsman's statement does not constitute a criminal or disciplinary finding against any individual.
The judge added: "In the unique situation presented by the Troubles it is appropriate that bereaved families should have the benefit of an independent investigative report such as this, particularly where no prosecutions have been brought."
Read more: Loughinisland families welcome dismissal of collusion challenge
