PSNI has not given Police Ombudsman Peadar Heffron information
The PSNI has not handed over information requested by the Police Ombudsman about the attempted murder of one of its officers, it has emerged.
Michael Maguire is taking Chief Constable Matt Baggott to court in a bid to obtain material on 60 murders.
The BBC understands that the Ombudsman has been trying to find out if police acted on information it was given prior to a dissident republican bomb attack.
Weeks later, Constable Peadar Heffron was seriously injured in a bombing.
It is also understood the PSNI has refused to hand over information requested by investigators looking at claims that police officers may have contributed to the death of former senior Sinn Féin official Denis Donaldson, who was also a police and MI5 informer.
As captain of the PSNI's Gaelic football team and an Irish speaker, Peadar Heffron was a high profile target for dissident republicans aiming to deter Catholics from joining the police.
In January 2010, he was critically injured as he left his home near Randalstown, County Antrim, to travel to work in Belfast.
The Police Ombudsman later received a tip-off claiming that weeks before the bombing, someone had warned the PSNI of a potential attack on an unnamed police officer.
We do not know the nature of the information. It may well be that it was so general or lacking in detail that nothing could have been done to minimise the risk to the officer.
The central point is that because police have been unwilling to spell out the detail, the Police Ombudsman is not in a position to reach any conclusions.
The police have also refused to give information to Ombudsman investigators probing the death of Mr Donaldson, who was shot dead at his remote cottage in County Donegal in April 2006.
He had fled there after being told by the police that the media were going to expose his role as an agent.
The Police Ombudsman is investigating allegations by his family that PSNI officers may have exposed him as an agent, and contributed to his death.
It is the kind of information that Michael Maguire told the BBC on Tuesday his office was legally entitled to obtain.
"Answering those questions requires access to quite a range of intelligence and other sensitive material," he said.
"I need access to that in order to be able to come to a view, in order to determine whether they are right or not."
The PSNI has said it had a legal responsibility for the management of all information that it holds, and that it could not release information if it could potentially endanger lives.
However, the Police Ombudsman and his senior investigators have top-level security clearance - the same as the chief constable and other senior police officers.
This means they can have access to sensitive intelligence material.
Dr Maguire's view is that because of this, the PSNI has no legitimate reason for refusing to provide the information he has requested.
He hopes to submit court papers within the next week to seek leave for a judicial review of the chief constable's refusal to provide the information.
The move is aimed at forcing the PSNI to hand over the material his investigators have requested.