Police defending the indefensible is no longer acceptable, a victims campaigner in Northern Ireland said.
Relatives for Justice (RFJ) chief executive Mark Thompson has supported families bereaved during the Sean Graham Bookmakers murders in 1992 among others.
He said police had denied relatives access to documents concerning the murders of their loved ones.
“One only has to look at the long list of cases where they have fought families in the courts to prevent disclosures and the publication of reports in murders by illegal paramilitaries.
“The ordinary public might ask why?
“The families bereaved and those injured might well guess the answer.”
Police have previously guarded against releasing information which could pose a risk to life, for example where it involved sensitive intelligence material or reveal the identity of sources.
Officers are bound by law to weigh that risk to life when making decisions.
The inspection report said police should immediately review their appointment and training of staff responsible for disclosing information.
Mr Thompson said the previous Ombudsman, Dr Michael Maguire, had to issue the threat of legal proceedings against the PSNI to obtain disclosures crucial to numerous investigations where collusion by the RUC was being investigated.
He added: “This was an unprecedented action.”
He claimed a culture existed of defending past actions of the RUC’s Special Branch.
“Defending the indefensible is no longer acceptable.”
The campaigner added: “The Ombudsman must have direct and unfettered access to all documents held by the PSNI as a matter of routine when investigating such serious incidents.”
Deputy chief constable Mark Hamilton said from the outset the force recognised the impact of the failure to disclose information to the Ombudsman on the families and the wider public’s confidence in policing.
“This failure was not due to the actions of any individual but was an organisational and systems failure and I unreservedly apologise again to the families for this.
“As soon as the issue came to police attention, we commissioned urgent work to address it, and over the course of the last year we have worked closely with Office of the Police Ombudsman for Northern Ireland and fully co-operated with the Criminal Justice Inspectorate to do so.”