Up to 50 murders allegedly linked to a top British spy within the IRA include other state agents who had “outlived their usefulness”, the High Court heard on Tuesday.
Lawyers for relatives of one victim also claimed the PSNI lack the “appetite” to investigate the activities of the Army’s prized intelligence asset, operating under the codename Stakeknife.
The allegations were made as a legal bid to have an outside police force carry out the probe was listed for a hearing in February.
Judicial review proceedings have been brought by the family of Caroline Moreland.
Ms Moreland, a 34-year-old Catholic mother of three from Belfast, was abducted and murdered by the IRA in July 1994 for being an alleged British informer.
Her children’s legal action is seeking to secure a wide-ranging investigation into the full circumstances surrounding a series of killings stretching back to the 1980s and attributed to the IRA’s internal security team.
In October Director of Public Prosecutions Barra McGrory QC called for police to examine Stakeknife’s activities, along with what was known by RUC Special Branch and MI5.
Although relatives of those allegedly killed by the IRA’s so-called ‘Nutting Squad’ have backed that move, they are opposed to the PSNI taking charge.
At a previous hearing it was claimed that west Belfast man Freddie Scappaticci was permitted to engage in the campaign in order to strengthen his position as a British spy.
Scappaticci left Nothern Ireland in 2003 when he was identified by the media as Stakeknife.
But before quitting his home he vehemently denied being the agent.
In court on Tuesday barrister Sean Devine, for the Moreland family, set out the reasons for wanting an outside police force.
“One of the criticisms is the PSNI don’t have any appetite for this investigation because it will necessarily involve criticisms of the security forces,” he said.
He claimed delay has been used as a method of avoiding such criticism.
Mr Devine added: “The position is that the families of the various deceased, and we are talking in excess of maybe 50 murders have been reported, are awaiting answers for a very long time.
“The core subject matter of this challenge is the use of a state agent to kill, amongst others, other state agents that had outlived their usefulness in the eyes of the authorities.
“The subject matter couldn’t be any more poignant or important.”
Counsel for PSNI Chief Constable George Hamilton indicated a final decision has still to be taken on how to respond to the DPP’s request.
Paul McLaughlin said: “I have been instructed that a range of options are under consideration by the Chief Constable.
“He has been engaging with a number of other bodies who may have an interest in the matter and he continues to do so.”
Consenting a request by the Moreland family’s legal team, Mr Justice Maguire listed the application for leave to seek a judicial review for hearing in February.
The judge will review the case again early next year to monitor progress.