Detectives are investigating three suspicious car fires in Upper Hutt, north of Wellington, early this morning.

Senior Sergeant Marc Clausen said all three cars were badly damaged.

The culprit was not seen at any of the scenes. The first fire was reported at 1.40am in Mcleod St, the second was at about 4.40am in Gillespies Rd, and the third was at 6am in Alleyne Court.

Fire safety officers and Hutt Valley CIB were meeting this morning to start an investigation.

Gillespies Rd resident Warren Jennings heard the alarm going off in his partner's car about 4.40am and went outside shortly after to see the Nissan runabout fully ablaze.

''She was on fire mate - someone had torched it ... she was humming.''

The car, which was uninsured but worth only $2000 or less, was a write-off.

''Some little arsehole burnt it. I can understand if someone was to nick it. To torch it, what is the mentality in that?''

While the car was parked on the street near the house, he never feared the fire would reach over.

Greg White, whose car on Alleyne Court was the most recently lit, said his cousin arrived to pick him up for work this morning and noticed what looked like steam coming from inside the white Mazda.

When White came outside he could see the windows were blackened, the quarter window was smashed, and there were embers inside the car.

He tried to unlock the door but the electric systems in his car had failed.

They put a hose in the smashed window but shortly after the back window smashed with flames coming out.

They hosed the fire until fire fighters arrived.

The interior of the car was ''gutted'' but he was thankful the car seat for his baby was in the family's other car.

He was insured.

- © Fairfax NZ News