Authorities have confirmed the deadly Longwood bushfire in central Victoria was started by a trailer throwing off sparks.

Scorching 40‑plus degree temperatures, bone‑dry conditions and strong winds created the perfect storm for the blaze to take hold before it tore through multiple country towns, destroying 150 structures and claiming the life of local cattle farmer.

Max Hobson, a man in his 80s, was found dead 100 metres from his ute and about 10 minutes from the property he shared with his wife.

It is the first fire-related death in a disaster which has spread to more than 400,000 hectares, with smoke visible from space.

Dom Rhoden feared for his mate Rowan Craven after having to leave him with a wet blanket and sheltering with sheep so he could defend his own home at Longwood East.

“That was also probably an hour and a half I spent thinking my mate was dead and trying to build up the courage to ring him to see if he’ll answer,” Rhoden told 7NEWS.

‘It’s horrific’

Kathy Munslow’s home was also saved.

“So many people have lost so much. It’s horrific,” she said.

She runs a sanctuary for animals that have been abused and had no choice but to leave them when she evacuated.

She returned to find all but one of her animals miraculously survived.

“Stuff can be rebuilt but they can’t be replaced,” she said.

A watch and act alert remains in place, with the fire still not under control, and CFA crews working around the clock to stamp out hotspots and stop the danger from flaring up again.

The number of buildings destroyed in fires across the state has increased again to 350, including 100 homes.

Up to 1000 agricultural properties have also been damaged.

Around 850 insurance claims have already been made, with donations flooding in at support centres.

Premier Jacinta Allan visited Natimuk, where about 30 homes were destroyed, to announce emergency assistance payments of up to $52,250 for uninsured households to re-establish their principal place of residence.

A Victorian bushfire appeal will open online from Tuesday for public donations.

“Every dollar will go to where it is needed,” the premier said.

She disputed claims of underfunding for the Country Fire Authority ahead of the bushfire season, saying her government had invested an additional $80 million for fire preparedness in November.

“To suggest that there’s been anything other than an increase to the funding for the CFA is just incorrect,” Allan said.

CFA chief officer Jason Heffernan said the budget for the service this year was $20 million more than last year.

He said “quite a number” of complained-about appliances had been removed and 167 new trucks were on order or in production.