The Army were called to Maghaberry prison yesterday morning after a suspect device was uncovered.
Details of where it was found were not made public, but it led to parts of the 1,100-inmate complex being evacuated.
The alert was sparked at around 10am and continued until it was declared an “elaborate hoax” around five hours later.
During the morning, the jail had been due to host a live video link-up as part of a court case concerning alleged members of the IRA.
Four men accused of membership of the organisation, and associated offences, were due to appear at Lisburn Magistrates’ Court via the link but were unable to be produced because of the alert, which had resulted in the prison being on “lockdown”.
Due to appear on videolink at the court were alleged terrorist leader Kevin O’Neill, 58, from Coolnasilla Park South, who faces charges of IRA membership and directing the activities of the proscribed organisation on dates between December 1, 2013, and June 25 this year; 37-year-old Robert Warnock O’Neill, from Bingnian Drive; Daniel McClean, 47, from Hannahglen Heights; and Mark Gerard Heaney, 48, from Lagmore Glen, all in west Belfast, who are also charged with IRA membership on the same dates.
Heaney’s defence lawyer Jon-Paul Shields withdrew a bail application as he had not been able to consult with his client given the lockdown.
District Judge Rosemary Watters listed the case again on August 18.