McMahon and his co-accused Noel Noonan (34) pleaded guilty last month to membership of an unlawful organisation within the State styling itself the Irish Republican Army, otherwise Oglaigh na hEireann, otherwise the IRA on February 7, 2013.
The pair were due to stand trial, but the case was adjourned in the wake of the garda taping revelations after the defence sought confirmation as to whether phone calls made by their clients with their solicitors prior to interview were recorded.
However, McMahon, of Ros Fearna, Murroe, and Noonan, with an address at St Patrick's Hostel, Clare Street, Limerick were subsequently arraigned and pleaded guilty to the charge.
They were remanded on continuing bail for sentence on June 27.
Last June, the non-jury court allowed McMahon, a father of two who had previously worked as a chef in Bunratty Castle, to travel to Lithuania to attend a family wedding.
Last October it again varied the bail conditions to allow him to go on holiday there.
In January of this year he was allowed to travel to Lithuania for a third time.
Counsel for McMahon, Michael Bowman BL, asked the court yesterday to facilitate one final trip to Lithuania for McMahon to allow him to visit his in-laws with his family.
He asked that McMahon's passport be returned to him and that the sign-on conditions be removed from May 2 to 16.
Tara Burns SC, prosecuting, said the State was objecting to the application.
Det Insp John Dollard told Ms Burns that gardai were objecting to McMahon being granted the facility because of the inability of gardai to supervise the bail conditions and because of McMahon's change in circumstances since the last variations were granted.
He said in essence that gardai believed there was a serious risk of a substantial custodial sentence being imposed and this would lead the defendant to consider not returning.
Det Insp Dollard agreed with Ms Burns that gardai were concerned McMahon was a flight risk.
Taking to the stand, McMahon told Mr Bowman that his intentions were to visit Lithuania as he would not see his family for a while and just wanted to say "good luck".
Mr Bowman told the court that €20,000 provided by McMahon's father by way of an independent surety represented the entirety of his savings.
Ruling on the application, presiding judge Ms Justice Iseult O'Malley said the court was minded to allow the order, but would make it clear that the passport should be returned to gardai on May 16.
If it was not returned, the State had immediate liberty to apply for estreatment (forfeiture) of the bail monies.