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28 July 2015 Last updated at 19:00 BST
Six cameras and a mobile detection unit were introduced last month to catch drivers illegally using the lanes, but a timing problem with the cameras has since been discovered.
Motorists who have been incorrectly issued with fines, when they had committed no driving offence, will now be refunded.
BBC Newsline's Michael Fitzpatrick reports.
A fault with bus lane cameras in Belfast has led to more than 700 fines being cancelled.