Auckland Airport has unveiled the scale of the delays today following an IT issue.

A fault with a fibre network provider's domains cut the internet to a number of businesses, including international check-ins.

It meant airlines had to manually check people in, causing several flights to be delayed.

The airport's chief operating officer, Chloe Surridge, says it caused a lot of disruption, until switching providers fixed the issue.

"There were 40 airlines running on delays in departures - and that kinda has a knock-on effect to probably about 20 arriving slightly delayed as well."

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