Police are calling for public assistance following a suspicious fire on Hanson St in Wellington on Sunday.
One person was taken to hospital after two properties were destroyed, and another two badly damaged by the major fire.
Detective sergeant Steve Wescott said several witnesses have come forward, and police has since seen CCTV footage, which shows two people leaving the address separately shortly after 10.30pm.
"On arrival, police located one injured person outside and were made aware
the property was on fire."
He said staff will remain on site for the next few days as an examination of the scene continues.
The blaze broke out in a property in Newtown just after 10.30 on Sunday night and it quickly spread to three other properties in Hanson St and Adelaide Rd.
It was brought under control by about 1am.
One member of the public was taken to hospital and two firefighters received minor injuries, but everyone else has been accounted for, with no other reports of injuries.
Hanson St resident Josh Godsiff, who lived in the house next door, spoke to the Herald on Sunday night as his home was ablaze.
"We were just about to go to bed and then we heard a bit of noise next door," he said.
"We came out of the house to have a look and we heard on the street one of the police guys opposite to the house ... he comes out and says 'get out now'."
Godsiff said his house was two doors down from the house that initially caught alight, which was believed to be abandoned. He had time just to grab his keys, phone and wallet before leaving the house.
Inquiries into the incident are ongoing and anyone with further information
is urged to call 105 or Crimestoppers anonymously on 0800 555 111 and quote
the file number 210614/4572.