Peter Mitchell from Seven News Australia
told Al Jazeera the police are investigating the fire which left 5,000 people homeless in Kingslake and killed at least 33 people.
"That fire started in a pine plantation. It's still not clear whether it was the work of an arsonist, but there's a fire down the Gippsland the police think was deliberately lit and the hunt is on for that pyromaniac."
Two people, including a teenage boy, have reportedly been arrested and charged with arson.
"Everybody's gone. Everybody. Their houses are gone. They're all dead in the houses there," Christopher Harvey, a resident of Kingslake, said.
"There are animals dead all over the road," he said.
Christine Nixon, Victoria police commissioner, told a news conference: "What we've seen, I think, is that people didn't have enough time, in some cases."
"We're finding [bodies] on the side of roads, in cars that crashed."
Some of the fires eased on Monday but thousands of firefighters and soldiers continued to battle dozens of blazes across an area of about 3,000 sq km across the states of Victoria, South Australia and New South Wales.
Mitchell said firefighters in the affected areas were facing difficulties tackling the blaze as swirling winds continued to spread the fire in different directions.
Residents so far unaffected by the fires were anxiously waiting to see if they would be hit by the devastating infernos.
"People are nervous, we are at the mercy of the weather," James Lacey, a businessman from the town of Yackandandah, said.
Kevin Rudd, the country's prime minister, said authorities expected the death toll to rise as firefighters and rescuers searched charred buildings and pulled the remains of dozens of people.
"This is of a level of horror that few of us anticipated. There are no words to describe it other than mass murder," he told Australian television.
More than 750 houses have been destroyed and around 80 people taken to hospital with serious burns and injuries.
Many patients had burns to more than 30 per cent of their bodies and some injuries were worse than the Bali bombings in 2002, said one doctor at a hospital emergency department.
Kieran Walshe, the police deputy commissioner for Victoria state, said the speed at which some of the fires took off indicated they might have been deliberately lit.
"Some of these fires have started in localities that could only be by hand, it could not be natural causes," he said.
Mike Rann, the premier of South Australia state, said on Sunday at least 20 per cent of the fires in his state were started by arsonists and another 20 per cent were the result of "stupidity or negligence".
"These people are terrorists within our nation, they are the enemy within and we have to be increasingly vigilant about them," he said.
Arsonists were also relighting fires that had been brought under control, Steve Warrington, a deputy chief of firefighting operations, told local radio.
"While we often think it is spotting [embers spreading flames], we also know that there are people lighting fires deliberately."
Victoria's bushfires are the worst natural disaster in Australia in 110 years.