Vets have checked out the monkeys that got a glimpse of freedom when a wall to their enclosure collapsed at Auckland Zoo.
The thick outer wall of the structure on Old Mill Road collapsed at about 10am, rupturing a gas main.
There were up to seven Bonnet Headed Macaque within a wire inner wall at the time.
The Fire Service was called out, and also helped to ensure there were no escape attempts.
Head of Life Sciences at Auckland Zoo Kevin Buley said his primate staff had assessed the monkeys to ensure none were harmed by the gas.
"It's fair to say it was probably a rude awakening for them this morning at 10 o'clock if they were having a lie in.
"But they've been throughly checked out. They might have been a bit disturbed initially with the wall coming down, but the gas doesn't seem to have affected them in any way."
Mr Buley said another wall near the collapse was being tested to make sure it was not likely to collapse.