A pregnant Manawatu solo mum is sickened by the actions of an arsonist who used her baby's birthday presents to fuel a fire that left the young family without a home or belongings.

Mother-of-two Sarena Check said her livelihood as an in-home early childhood educator had been taken away by arsonists who started a kitchen fire at her Savage Cres house in Palmerston North on July 2.

Detective Constable Jasmine Woollett said gang activity was being investigated in relation to the attack.

"She's a young mum with young children, this is quite devastating for her," she said.

"There's not a heck of a lot of damage but she doesn't feel safe in her own home and she has incurred a lot of costs. It's quite sad."

The culprits took items from Ms Check's daughters' rooms and clean laundry to use to start the fire.

They doused her youngest's new toys with an accelerant and set them alight atop a gas oven, only a week after they were given to the girl on her first birthday.

The strong stench of burnt plastic still lingered at the house yesterday, which the young family has been locked out of in the weeks after the fire.

"We have nowhere to stay, they have taken our home away from us," Ms Check said.

"I don't know how people could comprehend that something like that is okay.

"They saw that kids lived there and went and got the babies toys out of their rooms to start a fire. That is sick."

Ms Check, who moved from Whanganui to Palmerston North six months ago, said she had been left near destitute by the attack.

Toxic smoke had damaged and destroyed the family's possessions and the house was uninhabitable for several months, while the owners repaired it, she said.

"The fire itself wasn't large but because they used accelerants and stuff to start the fire it went through everything."

She discovered the fire on the Monday evening when she was returning home.

Smelling the fumes, she followed the billowing smoke to its kitchen source and called emergency services.

Ms Check said she did not have insurance, and was now unemployed as she had opted to spend the final two trimesters of her pregnancy at home with her children working as an in-home early childhood educator.

"I didn't even really think about insurance or think that this would happen, and trust me – it's been drummed into my head ever since," she said.

"When you're a single mum, insurance is the last thing you think about when you've got babies and work to think about, too."

Ms Check said her 7-year-old daughter was unaware she had lost her home and had been sent back to Whanganui to stay with her grandparents.

"She has a lot in her room and all of that is quite special to her," she said.

"I know she's going to be so upset when she realises that she's lost a lot and that we have to move again."

The family was able to stay with friends in the meantime, but had approached Housing New Zealand for assistance in finding a home.

Detective Sergeant Craig Sheridan said arson was a potentially devastating crime as even the smallest fire could grow to cause massive damage.

He called for anyone with information to contact police on 063553655.

- © Fairfax NZ News