THE senior garda appointed to investigate allegations of perjury against two detectives during the Omagh bomb trial was at the centre of an extradition case in the 1980s thrown out by the Supreme Court because of what they described as "police illegality".

Detective Superintendent Cormac Gordon was criticised by a High Court judge for giving "most unconvincing" evidence on oath when the detention of Australian mafia boss Robert Trimbole was ruled unlawful in 1985.

Gordon was this year appointed by Garda Commissioner Pat Byrne to investigate allegations that two detective gardaí perjured themselves during the Omagh bomb trial of Colm Murphy.

Responding to questions from The Sunday Tribune a garda spokesman said: "the question as to this officer's ability does not warrant a response. We are not going to comment on something dealt with in a court 18 years ago".

The extradition attempt and its subsequent collapse was an international embarrassment. Trimbole was wanted for a range of serious offences including murder and heroin dealing.

Gordon was criticised by High Court judge Seamus Egan as having given "most unconvincing" evidence about the reasons that he arrested Trimbole. In a landmark judgment on police accountabilty the Supreme Court upheld Egan's ruling and warned that the courts would take a hard line on "police illegality" in the future.

Gordon, then a Detective Inspector arrested Trimbole, who used the alias Michael Hanbury, in October 1984. The Australian was arrested under Section 30 of the Offences Against the State Act, which allowed gardaí to extend his detention for more than 24 hours. At the time of Trimbole's arrest there was no formal extradition arrangement between Ireland and Australia.

At 7pm the day after his arrest, Trimbole went to the High Court to challenge the legality of his detention. The case was heard by Judge Seamus Egan. During the hearing Gordon gave evidence that based on information from another garda inspector (who also gave evidence) he believed that Trimbole had "been in possession of a firearm and ammunition at the Gresham Hotel" on 24 October.

"I was satisfied after hearing the evidence that no genuine suspicion could have been formed by the gardaí in relation to possession by the prosecutor of any firearm or ammunition and I found as a fact that the evidence as to the genuineness of the suspicion was most unconvincing, " Egan ruled, ordering Trimbole's release.

The Australian was rearrested in the precincts of the Four Courts by Gordon with a warrant under the 1965 extradition act which had been signed into law just hours earlier by government order.

"At the subsequent hearing before me that night Detective Inspector Gordon swore on oath that at no time from the time of arresting the prosecutor on the 25 October 1984 under the name Michael Hanbury up to the time of giving evidence before me between the hours of 7.00 pm and 10.00 pm on the 26 October 1984 did he believe the prosecutor to be any person other than Michael Hanbury. I do not accept his evidence, " Egan ruled.

The judge concluded that the only "rational explanation" for arresting Trimbole under section 30 was to ensure that the fugitive "would be available for arrest and detention" when the extradition act was extended to include Australia.

"There was a gross misuse of section 30 which amounted to a conscious and deliberate violation of constitutional rights. There were no extraordinary excusing circumstances, " Egan ruled.

The release was appealed by the state to the Supreme Court which dismissed the appeal.

The Supreme Court ruled that gardaí should not think that "conduct of this kind" would simply result in a "judicial rebuke".

Instead the ruling stated that courts would enforce constitutional rights and if that resulted in a fugitive escaping justice "then such consequences are not of the courts' creation; they stem from the police illegality".

Trimbole died on the run in Spain in 1987 and never faced trial in Australia for his offences.

Gordon's appointment this year followed a finding by the Special Criminal Court that the final page of a statement obtained from Colm Murphy by Detective Gardaí Liam Donnelly and John Fahy had been rewritten. The gardaí had denied on oath that the statement had been amended.