Man dies in hospital after fire tears through home guarded by barbed wire

It took fire crews 30 minutes to locate a unconscious man buried under hoards of belongings as fire tore through his inner-western Sydney home, according to neighbours.

Mark Hosking died in hospital after the fire tore through his two-storey duplex on Stanley Street in Putney, near Ryde, shortly before 4am on Saturday, police said.

Around 30 firefighters were called to the blaze, where they were forced to battle barbed wire fences and hoards of household items to access the property.

Fire fighters say they couldn't move through the home quick enough to locate the victim.

"The main body of fire appeared to be in the basement and the resident was found unconscious on the upper levels," a Fire & Rescue NSW spokesman said today.

"The unusually high levels of household materials being stored definitely inhibited the ability of the resident to escape from the building, and inhibited firefighters from being able to find the resident."

Three neighbours - one of them in a wheelchair - were forced from their homes by the ferocious blaze. They were treated for smoke inhalation.

A firefighter was also taken to hospital and treated for heat exhaustion.

“The conditions were terrible and the fire crew has done an amazing job being able to get here so quickly and extinguish the fire so quickly,” Inspector Bradley Smith said.

Describing the spread of the flames, neighbour Carol Jones told 9NEWS that the scene was "horrific".

"(The smoke) was really, really thick and it seemed to start from the front of the house but then it was coming over the roof at the back," she said.

FRNSW were faced with "a whole range of security measures" including barbed wire fencing at the home, which could be described as a hoarder's residence given it was filled with piles of various items, he said.

The man, believed to be the only person who lived in the building, was taken to nearby Concord Hospital in a critical condition but later died, police said.

He is yet to be formally identified.

A number of pets were found dead inside the home including snakes, kept in various terrariums, and a dog.

Some snakes were found alive, the FRNSW spokesman said.

One firefighter was treated for exhaustion while three neighbours, forced to evacuate their properties, were taken to hospital for observation suffering smoke inhalation.

Neighbour Sam Manafikhi told 9NEWS he first thought the incident may have been linked to a gas leak.

”I saw everyone, police, fire brigades all around. I wasn’t sure what was going on,” he said.

”I was really concerned that it was a gas leak… It’s really sad to hear that and I hope everyone is okay.”

The cause of the fire is not yet known but a crime scene has been established ahead of a forensic examination.

With AAP.