A late night mystery phone call to the Garda Ombudsman headquarters at the centre of a spy scare may never have happened, Justice Minister Alan Shatter has claimed.
A UK-based counter-surveillance company Verrimus recorded an unexplained call-back at a speaker-phone in the offices when it sent a test signal down the line during a security sweep last year.
It was one of three "anomalies" identified in its communications system which has provoked a massive controversy over suspected bugging at the watchdog's headquarters in central Dublin.
In fresh revelations, Mr Shatter said an Irish IT security company Rits - which he called in to investigate the UK firm's findings - has come up with a "theory" that the mystery ring-back never happened.
Before a parliamentary committee on the bugging allegations, the justice minister said a telecoms company which controls lines in the Garda Siochana Ombudsman Commission (Gsoc) offices could not track any external call at the time it was recorded.
Rits - which says it counts a number of Irish government departments among its clients - has told Mr Shatter the ring-back may have been a signal bouncing back from a phone in the reception, which is used to distribute calls throughout the office.
"It may well be the case that there was nothing sinister about it, it may be the case that there was something sinister about it," he told TDs on the Committee on Public Service Oversight and Petitions.
Mr Shatter confirmed that a ring-back did not happen on follow-up tests.
In a further twist to the saga, the justice minister said there was also doubt cast over another feared security breach, where a suspected hi-tech eavesdropping device which could intercept calls made on UK-based mobile phones was discovered.
The IMSI (International Mobile Subscriber Identity) technology - which was alleged to be Government-level equipment - could actually be bought on the internet for 5,000 euro, said Mr Shatter.
He told the parliamentary committee that he did not consider it government-level technology.
Also, he said Rits had concluded in its review of the original Verrimus security sweep that it may not have been an IMSI device that was detected, but may have been technology used to boost mobile phone signals.
Mr Shatter has already suggested concerns about the security of a wi-fi device in the Gsoc headquarters could be explained by a network being inadvertently picked up from an Insomnia coffee shop underneath the offices.
The minister has launched an inquiry - headed by a High Court judge - to investigate the claims and counter-claims, as well as the differences between the reports by Verrimus and Rits.
"Go figure. I hope the judge can," said Mr Shatter.
"Because I don't have the technical knowledge to adjudicate between those issues."
Gsoc, Verrimus and Rits have all agreed to co-operate with the inquiry, Mr Shatter said.
The High Court judge will be able to invite witnesses for questioning.
Mr Shatter said that because the Rits report was a "peer review" of one of its competitors, certain elements would not be suitable for general distribution, although its report would eb fully available to the judge.
Asked if he had authorised surveillance of Gsoc, Mr Shatter replied: "Of course I haven't."