The cause of a fire that killed three people in Hamilton last year remains undetermined but is still being treated as serious as police continue their investigation.

Tauranga man Joseph Soutar escaped the blaze that claimed the lives of his flatmates in November 2014.

Fire gutted the Collingwood Street villa in November.

Jake Lindsey Hayes, 19, Toni Maree Johnston, 23, and Connor James Swetman, 17, died in the fire at the Collingwood Street flat on Saturday, November 15.

Three days after the fatal fire, Joseph paid tribute to his flatmates. Read more here.

Detective Senior Sergeant Ross Patterson says forensic results from the Collingwood Street villa failed to find the exact cause of the blaze.

He says: 'As a result of the fire an examination of the scene was conducted and a number of exhibits were removed for forensic examination.

'To date the cause of the fire remains undetermined but we are continuing our investigation and we will be reviewing our exhibits to determine if any further analysis is required.”

Ross says though police are not seeking any particular person in relation to the fire at this time, the case remains open.

'The fire remains unexplained; to that end the matter is still being treated as a serious one and will continue to be so until such time as information is at hand to provide confirmation on what caused it to start,” he adds.

'The families of the trio who lost their lives had been kept informed throughout the investigation and they are dealing with their loss as best as they can.

'Those involved in the investigation remain committed to providing those families with the answers about what occurred that they deserve.”

A firefighter dampening down hot spots following the fatal fire.