A korora/little penguin was seen waddling around the Market Reserve near the Oval early on Thursday.
The pint-sized penguin was able to go undetected by a police search about 1.30am but its luck ran out a few hours later.
Mechanic Tim Greene had just arrived at his work in Bond St when he saw the penguin stumbling along the gutter.
Immediately he knew something was not quite right."I thought that’s not normal; we’re at least half a kilometre away from the wharf.
"Then when my off-sider next door got in we made a couple of calls to Doc and they came and got him."
Before the Department of Conservation rangers arrived, Mr Greene had to coax the at-risk native bird out from underneath a parked car.
"It was a bit grubby but apart from that he looked pretty happy and was just out for a bit of a look around."
Department of Conservation biodiversity manager Jim Fyfe said the penguin was released into Otago Harbour and by all indications was in good health.
It was extremely unusual for a little penguin to be seen so far into the city and how it got there remained a mystery, Mr Fyfe said.
"You never know it might just be an adventurous penguin and maybe we’ll see it there again in a couple of days," he said.
A police spokeswoman said they had received a call about 1.30am after the penguin was spotted in Market Reserve and a unit was dispatched.
However, it was unable to locate the bird.