A judge in Newry Crown Court “stayed” the case against the officers, who were alleged to have perverted the course of justice by making a false statement regarding an incident in Armagh in June 2014.

The judge found that the officers were unable to receive a fair trial due to various investigative failures by the Ombudsman.

The Police Federation for Northern Ireland said it felt a need to challenge “significant and worrying shortcomings” in the case.

Mark Lindsay, chair of the Police Federation, said: “If the standard of the evidence presented by the Ombudsman’s Office had such shortcomings or was deficient, then officers must be able to access a meaningful and independent complaints process.

“The case was never stronger for a rigorous system that allowed officers the right of appeal against Ombudsman recommendations.

“There were significant and worrying shortcomings in this particular case, and that causes our officers justifiable concern.”

Mr Lindsay added the Ombudsman had to address fears it “may be recommending prosecution of police officers where it is not justified”.