A man’s body has been found after an “intense” fire caused the roof of a suburban home to collapse.

The home on Irrara St at Croydon, in Sydney‘s inner west, was reported ablaze at about 4am on Wednesday.

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Six trucks and almost two dozen firefighters attended the fire, entering the back of the property due to “intense” flames at the front of the single-story red-brick house.

Part of the roof collapsed as firefighters were inside, forcing them to retreat, Fire and Rescue NSW said.

“The body of a person was located inside the home,” NSW Police said.

The man is yet to be identified, but is believed to be an 80-year-old man who lived at the home.

Footage taken after the blaze was extinguished shows a large portion of the roof caved in and firefighters examining other parts of the extensively damaged home.

An elderly woman is currently providing information to police.

She left the home at about 1am and was not present for the fire, Superintendent Christine McDonald said.

“Police were not called to the location prior to this fire,” she said.

At this stage, police are treating the fire as suspicious.

The cause of the fire is currently unknown.

Police are searching for a man who also resided at the home.

He is Caucasian, aged in his 50s, about 190cm tall, has a large build and short brown hair.

He was last known to be in the Leichhardt area and may be travelling on public transport through the inner west, Circular Quay, Watsons Bay, and surrounding areas.

The man is known to police, McDonald said.

Officers currently have concerns for his welfare, she said.

All three people are understood to be related and live at the home together.

McDonald said the man “has lived such a full life” and the family is “so devastated by what has occurred”.

“It really is tragic.

“We don’t like to see anyone die in these circumstances.

“To live such a full life and then to pass away like this is just an absolute tragedy.”

The family has lived in the area and is well known to the “tight-knit community”, McDonald said.

“It’s really tragic for everyone to have police and fire in their street.

“I just encourage everyone to reach out to support services if they need to.”

- With AAP