A car that burst into flames, destroying itself and another car in a Bay of Plenty garage, is an 'extremely rare” event, according to a car expert.

Anthony Thompson, an IT professional at Tauranga Port, was left 'stunned” on Wednesday to see the damage the early morning fire had wrought through his double garage at his Pāpāmoa home.

His two cars that had been parked there overnight – an electric Nissan Leaf, and a Mazda Atenza – are now unrecognisable mounds of pungent black metal, but Anthony is just relieved the flames didn't reach the house.

'Our house is separate to the garage, so we are lucky that that didn't catch fire too and that I woke up in time to get us all out.”

Anthony was asleep with his wife and two children when he suddenly woke up to a huge bang just before 6am.

'There was a huge bang, and then like the sound of a crash, so I got up to look outside and was shocked when I saw flames. We quickly woke up the kids who were a bit scared as they are only four and two.”

A neighbour helped alert others nearby until firefighters quickly arrived to extinguish the flames.

When Bay of Plenty fire safety investigator John Rewi arrived later to assess the damage, Anthony was surprised to learn it was the Mazda, not the electric Nissan, that had caused the fire.

'Everyone was thinking it must have been the electric car that started it, but we've already had a fire investigator who said it was the brakes on the Mazda, parked on the right. Then the fire spread and caused the other car to go up as well.”

Fires caused by lithium batteries in electric vehicles can burn longer and have been known to re-ignite, which led Anthony to presume at first that it had been his electric car that had caught fire first.

He doesn't know how brakes in the Mazda could have caused a fire.

Anthony Thompson outside his garage on Wednesday.

John says his investigation is ongoing and not yet complete, but that it was definitely the Mazda that burst into flames and initiated the fire.

It's the first time he had come across a situation where a car had caught fire after being parked for some time.

'Brakes can absolutely cause car fires as there's a brake pad rubbing against a metal disc and if that friction causes heat then this can cause sparks.”

He says it's apparent it was the Mazda from the direction of the flames and the damage to the back right-hand side where he believed it started.

'I'm still in the process of the investigation, but that is my first assessment of the situation.”

Motoring safety commentator and writer Clive Matthew-Wilson. Photo: The Dominion Post/Stuff.

Motor industry expert and editor of the Dog and Lemon Guide, Clive Matthew-Wilson, says it's 'extremely rare” for brakes to cause a car to spontaneously burst into flames while parked in a garage.

'People shouldn't panic that this could happen to their car. It is possible but as unusual an event as being hit by lightning or winning Lotto.”

Brakes normally caused sparks when something became lodged near them, such as a leaf, twig, old paper or rag.

'If something from the road gets caught and gets stuck there, then friction can eventually set it alight, just like rubbing twigs together when you are camping.”

Car fires are more commonly started when debris gets stuck in exhausts rather than brakes, he says.

Only days earlier, a ute had been recalled in New Zealand over a potential fire risk issue relating to the model's transmission.

In 2010 some Jeep and Chrysler models were recalled over brake and wiring issues that posed safety challenges, Matthew-Wilson said.

Several Mazda Atenza models in New Zealand had been subject to recalls over issues with airbags, but none over brakes, according to Waka Kotahi's database.

-Annemarie Quill/Stuff.