Two pig dogs were burned alive after thieves stole a Toyota Hilux and torched it.

Chad Scrivener, 22 and his brother Theo, 24, from Broadwood, 48km southeast of Kaitaia, lost about $10,000 worth of hunting gear and cash in the fire that a senior firefighter has called "absolutely despicable".

But their family is also devastated by the cruelty inflicted upon the two pig dogs in dog boxes on the rear of the ute on Friday night, in preparation for a hunting trip.

The brothers had set the ute up on their Awaroa Rd property for a hunting trip and the dogs were sleeping in dog boxes on the ute's tray.

The ute was stolen on Friday night when the brothers left the property briefly.

Father Malcolm Scrivener said those responsible for the sickening act rammed the front gate to his sons' property using a car, burgled the house, found the ute's spare keys, and drove off, leaving their car behind.

"They crashed the ute into a [Awaroa Rd] paddock then came back just before daylight to take the car away which they'd left behind, but [they] could not do so.

"They then got petrol and set the Hilux alight knowing full well the dogs were in there. All they had to do was to open the door of the dog box and let them out.

"You can replace all the other stuff but you can't replace those animals. Who in the world would be so sick to burn animals?" Mr Scrivener said.

He said the dogs had been taken on hunting trips for many years.

Mr Scrivener said his family knew the people responsible but would not name names as police investigations were underway.

He said Theo and Chad, 22, have been doing well as beekeepers and it was a shame they were victims of a "sickening" act.

Ahipara Fire Brigade officer in charge Dave Ross said it was an "absolutely despicable" act, the likes of which he has never seen.

"It's a very different level of theft. Theft of vehicle is one thing but when the vehicle is set alight with animals in it, it's just unbelievable. Very alarming to say the least. I've never ever seen it before."

Mr Ross said the dogs would have died from a combination of heat, fumes and burnt materials.

"I certainly hope police catch the perpetrators because it's a level of violence that saddens us all," he said.

One of the three dogs managed to slip out of its box and was found on the roadside.

Whangarei police Senior Sergeant Darren Sullivan said a report was received about 3.40am on Saturday that a property on Awaroa Rd had been broken into.

Police attended the scenes and are investigating the matter.