The new memorandum follows months of discussions prompted by police failures to disclose “significant” evidence related to legacy cases to the watchdog.

The memorandum includes a provision that, where lawful and appropriate, PONI staff will be able to access PSNI information systems directly.

Police Ombudsman Marie Anderson, who took up office last summer, having previously managed the Information Commissioner’s Office (ICO) in Northern Ireland, welcomed the agreement.

“From the beginning I wanted to become more directly involved and get a detailed understanding of how police search their vast estate for material,” Ms Anderson said.

“I soon came to the realisation that my investigators needed to be involved at every stage of that search on occasions.

“I know that providing us with information has at times been difficult for police, not least because of the vastness of the task but also the legal duty on all of us to protect the most sensitive of information.

“But the public must have confidence that police provide my Office with all the information it asks for.

“Both the Chief Constable and I agree such disclosure is central to confidence in both our organisations.

“I believe this agreement will allow for better searching for and sharing of this information.”