Police have confirmed a “suspicious” fire after a vigilante search for the remains of missing woman Breanna Muriwai was deliberately lit.

The fire at the property, which had been vacant for a number of weeks, occurred shortly before 6pm on September 15.

“A scene examination has been completed, which confirmed that the fire had been deliberately lit,” police said in a statement today.

Police recovered what they believe to be a “crude incendiary device” from the property on Rangiwahia Rd, Manuwatū.

“Relevant CCTV footage has been obtained and is being reviewed to see if it offers any lines of enquiry,” said a police spokesperson.

A convoy of vehicles travelled north from the Kāpiti Coast towards Mangaweka, south of Taihape on September 15, as part of the ongoing search efforts organised by Muriwai’s mother, Jasmin Gray.

Gray claimed to know her daughter’s remains were in the area and had organised a vigilante search supported by locals for information.

Jasmin Gray holds a photograph of her daughter Breanna Muriwai. Photo / Woman's Day

In a post to Facebook on Sunday evening, Gray said: “We’ve all had a massive day today and we can say that we have found items of interest”.

She added that they were now waiting on authorities to do “their mahi”.

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That same evening, emergency services were called to the rural settlement of Rangiwahia, about 20km from Mangaweka, following reports of a fire.

A Fire and Emergency NZ (Fenz) spokeswoman said they received calls to a house fire about 5.50pm. Upon arrival, fire crews found a single house and shed on fire.

Police are continuing to appeal for sightings of missing woman Breanna Muriwai, aged 22. Picture supplied by Police

“It was unoccupied at the time,” the spokeswoman said.

Colin Richards, who lives down the road from the property, said the search team left about 5pm, and the alarms for the fire went off about 5.15pm.

“The building was well alight,” said Richards, who noted there were three separate fires - one in the barn, one behind the barn, and one in the house.

“The house being, obviously, in the condition it was in, went up very quickly.”

The mass search of the property followed a warning from police against the action, saying it may destroy or compromise crucial evidence.

After the fire, neighbours say the Wellington-based officer in charge of the investigation visited the property as officers sifted through singed wreckage and focused on a green house bus.

Police are refusing to be drawn on what was found or provide any further updates.

A police spokesperson yesterday said while they understood people were genuinely intending to help, the best thing the public could do was “talk to us”.

“Police are still treating her disappearance as a missing persons investigation,” Detective Senior Sergeant Dave Thompson said.

Muriwai, who was 22 at the time of her disappearance, was last seen in August 2022 at Te Horo Beach. Searches were carried out for her, and her movements on the night she disappeared were examined by police.

Police are urging anyone with any relevant information to come forward.