Oranga Tamariki is looking into the care of a two-year-old found alive inside a suitcase in a bus luggage compartment.

The toddler was found early Sunday afternoon by a driver of an InterCity bus from Whangārei to Auckland.

A 27 year old woman has appeared in North Shore District Court charged with ill-treating a child.

The child had been in the suitcase for nearly an hour wearing only a nappy, RNZ understands.

Police were called at 12.50pm after a passenger asked for access to the luggage compartment during a planned stop in Kaiwaka, Northland.

Detective Inspector Simon Harrison said the driver became concerned when he noticed the bag moving.

"When the driver opened the suitcase, they discovered the two-year-old girl," he said.

Harrison said the little girl was reported to be "very hot", but otherwise unharmed.

She was taken to hospital in a "minor" condition for an extensive medical assessment.

"We would like to acknowledge and commend the bus driver, who noticed something wasn't right and took immediate action, preventing what could have been a far worse outcome," Harrison said.

The bus had stopped at this Kaiwaka carpark leading to the Tulip Cafe, Motel. Photo: Kim Baker Wilson / RNZ

"Police inquiries into this incident are ongoing and further charges cannot be ruled out. Oranga Tamariki has also been notified."

An InterCity spokesperson said the company was aware of an incident involving a passenger on one of its services earlier on Sunday.

"Police were called to respond, and they are now investigating the matter.

"No one was harmed during the incident and the service has resumed. As this is now an active police investigation, we are unable to comment further."

Locals in Kaiwaka said they were shocked and saddened to hear what happened to the toddler.

Kristel Faber who worked in the Kaiwaka Cheese Shop said the incident was "bizarre".

"Just the thought of someone having that idea, putting a toddler in a suitcase... How can people think about doing that..."

Another local woman who wished to remain anonymous said the situation was very sad.

"I was deeply saddened to hear such a thing, I mean who does that, puts their child in a suitcase and the suitcase is locked away with the other luggage?"

She said knowing the toddler was alive and physically unharmed was a relief.

"I can't fathom how the bag was put in the bottom of the bus and not identified that there was movement in there at the time. I'm unsure about that, how did it get that far anyway?"

Oranga Tamariki said it was working with the child's family to ensure they were safe.