Updated July 24, 2016 14:42:12

Photo: The fire at Niddrie is believed to have been started by a heater. (ABC News: James Hancock)

A 98-year-old World War II veteran has died after a fire engulfed his home of more than 50 years in Niddrie, in Melbourne's north-west.

The alarm was raised when a medical alert was activated at Fred Smith's home on Vaynor Street at 5:30am.

When paramedics arrived they found the single-storey brick house on fire.

They then discovered Mr Smith's body on what is understood to be his favourite chair. There were no other occupants.

It appeared he had placed clothing on top of a heater, which was also too close to a couch, the Metropolitan Fire Brigade said.

Mr Smith had a smoke alarm with a fully-charged battery but the unit had not been connected correctly.

The MFB said the fire had been going some time before they were alerted but the lack of oxygen in the house meant the fire was contained to the lounge room.

It was understood to have begun about midnight and slowly burned until authorities arrived more than five hours later.

Neighbours said Mr Smith had moved into the home in the 1950s and had once worked for Ansett. He was a member of the East Keilor RSL club.

His wife passed away a number of years ago, they said, and his 99th birthday was just six weeks away.

He had only stopped driving about four years ago and had not been well for some time.

Neighbour June Chambers said she had known Mr Smith for more than 50 years.

"It was an awful way to go," she said.

"I've been here for over 60 [years]. He was just a lovely man, and he was a very wise man, too. He knew lots of things.

"Very interesting to talk too. He liked to have a chat with the neighbours."

Topics: fires, community-and-society, niddrie-3042, melbourne-3000, vic

First posted July 24, 2016 08:46:13