An alleged assault victim has cleared the first stage in his High Court challenge to the withdrawal of a charge against the man he claims attacked him.
Christopher Mooney was granted leave to seek a judicial review after the Public Prosecution Service accepted it failed to fully explain the reasons for the move.
Even though counsel for the PPS said the case was conceded, a judge ruled that a further hearing was still necessary.
Mr Mooney claims he was subjected to a "vicious and sustained assault" at a house in Belfast five years ago.
He took legal action against the PPS after it was decided to end criminal proceedings against a man who had faced a court summons over the incident.
His barrister, Sean Devine, today contended: "The respondent accepts that the manner in which the decision was arrived at was unlawful."
Peter Coll, for the PPS, confirmed it had not been made properly and should be retaken.
"The PPS accepts now it was made contrary to its policy," he said.
Mr Coll argued that the man who allegedly assaulted Mr Mooney would not suffer any prejudice by a successful legal challenge.
It would only lead to a fresh decision being made which, if it was to reinstate the criminal case, could be contested at the Magistrates' Court, he pointed out.
But a barrister for the alleged attacker contended that reasons for withdrawing the case were given: delay and the belief that Mr Mooney had moved to England.
He also questioned Mr Mooney's account of the incident, pointing out that a police caution was initially suggested as one possible outcome.
"It does not meet the description of a vicious and sustained assault, and perhaps explains why the PPS took the course it did," the barrister said.
However, Mr Justice Stephens ruled that Mr Mooney had cleared the hurdle of establishing an arguable case.
Granting leave to seek a judicial review, he said: "The PPS accept that they failed to explain to the applicant Mr Mooney why it was considering whether to withdraw the criminal prosecution."
The judge added: "In such circumstances where the PPS accept that there has been a failure to comply with their own standards there may arise a question in relation to the appropriate remedy."
But despite being informed that the challenge was not being contested, he held it was in the public interest to continue to the next stage early in the new year.