|The Country Fire Authority says it is unsure of how many arsonists there are, or their identities, but has confirmed that some of the fires raging across tens of thousands of hectares are being deliberately relit.
Steve Warrington, the deputy chief of CFA operations at the emergency centre, says a blaze burning in Churchill in the Gippsland region is spreading faster than expected due to suspected arson.
"We had predictions yesterday that we thought there would be spotting of about seven or eight kilometres," he told Local Radio.
"We know we do have someone who is lighting fires in this community. While we often think it's spotting, we also know that there are people lighting fires deliberately."
But he says even without arson, the fires have burned more intensely than anyone anticipated.
"A lot of these fires actually went over expectations," he said.
"This was one of them. It actually exceeded expectations and went towards the coast."
At least 35 people have been killed and more than hundreds of homes have been destroyed in what Victorian Premier John Brumby has described as the worst weekend in Victoria's history.