Auckland Transport says city rail services have resumed and were expected to be fully operational by 2pm.
The signal system failed at 11.15am, stopping all trains on the network for an hour and a half.
Auckland Transport is apologising for the suspension of train services across the city and tweeted that although trains were now working passengers could expect some delays and cancellations.
Due to a Kiwirail signal issue, Britomart has been closed until further notice. All services that are at train station platforms are off-loading customers, whereas all services between train stations are waiting for an update to move and have customers off-loaded safely. https://t.co/Wd1lPP9mVH— Auckland Transport (@AklTransport) June 13, 2019
Affected trains were moved to the nearest station so passengers could get off.