A security alert at Maghaberry Prison, which was sparked by the discovery of a suspicious object, has been declared an "elaborate hoax".
The high security facility on the outskirts of Lisburn was on lockdown following a report of a suspicious object found within the prison estate on Monday morning.
Army bomb experts attended the scene.
"These security incidents are becoming more and more frequent, a worrying factor to the security situation in Northern Ireland," said UUP Justice spokesman Tom Elliot.
"Just this week, we have been told of the financial pressures facing the PSNI and these continued threats are stretching policing resources to the maximum."
A Prison Service spokesperson confirmed: "The security alert at Maghaberry has now ended following confirmation from the PSNI that the device was an elaborate hoax."
The hoax alert may cause some disruption to legal visits, the department of Justice has warned.
Anyone intending to visit the prison on Monday should telephone prior to visiting.
© UTV News