The nation's biggest and busiest international airport terminal at Auckland was effectively shut down at the height of the city's rush hour this evening because of a gas leak.

The leak at the Novotel construction site in the car park area was reported to have occurred after a pipe was hit by a digger.

Police said tonight traffic was being diverted at the intersection of Tom Pearce and George Bolt Memorial Drive.

The leak was not reported to be endangering aircraft movements at Auckland International Airport (AIA), but the terminal and the carpark were evacuated.

No estimate was available as to when the leak would be repaired.