STAB vests have been purchased for security staff at the Stormont assembly following a fatal knife attack on a police officer outside Westminster last year.
The Assembly Commission said that a total of 61 stab vests, costing more than £22,000, have been bought under a contract signed in January.
The figures were released in response to an assembly question from TUV leader and North Antrim MLA Jim Allister, who said he has no issue with the costs and hopes the vests "are never needed".
PC Keith Palmer was fatally stabbed outside the Houses of Parliament in London in March 2017 during an attack by Khalid Masood.
In November 2006, loyalist Michael Stone managed to make his way to the entrance of Stormont with an axe, garrotte, imitation handgun, three knives and homemade bombs, as part of an attempt to kill Sinn Féin leaders Gerry Adams and Martin McGuinness.
Stone, who was jailed for 16 years for the attempted attacks, got halfway through the revolving doors at the front of parliament buildings before security staff wrestled him to the ground.
An Assembly Commission spokesperson said the vests are "a responsible and balanced measure" aimed at "affording a greater level of personal protection to staff in their front line role".
"Particularly in light of knife attacks in Great Britain in 2017 which included the fatal stabbing of a police officer outside the Palace of Westminster," said the spokesperson.
"Protective stab vests are also worn by security staff at the Scottish Parliament and the National Assembly for Wales."
Meanwhile, the commission has revealed that a portrait of the former deputy first minister Martin McGuinness cost £5,000.
It was unveiled in front of his family in the Great Hall at Stormont on the first anniversary of his death in March.
The framing of the portrait cost an additional £320.
Under a policy agreed in 2009, an official portrait of each speaker, first minister and deputy first minister is painted to mark their time in office, within a budget of £5,000 per portrait.
The Assembly Commission said that two former speakers, Willie Hay and Mitchel McLaughlin, declined a traditional painted portrait and instead launched a competition in conjunction with Ulster University for students or recent graduates to be commissioned to take their photographs.
