THE Victorian Government will audit components of its bushfire alert system after flaws were uncovered during Tuesday's bushfires.

Residents in the path of a fast-moving grass fire near Ballarat revealed they were not warned by SMS about the oncoming blaze.

Others complained they could not get crucial and time-sensitive information on the CFA website.

The fire ripped through the Chepstowe area on Tuesday afternoon, injuring six people and destroying eight homes.

Irate residents being debriefed at the nearby Snake Valley Town Hall complained text message warnings either never came or were sent two hours after the fire had begun about 3.30pm.

Carngham resident Lauren Jacka said they had received the mobile alerts far too late.

"We got the SMS two hours after the fire started. We could well have lost everything if the wind turned around," she said.

Another resident asked CFA officials why they did not receive a text at all.

"What happened to the text messages?

"What are the people in the so-called grey areas supposed to do? Burn?"

Fire Services Commissioner Craig Lapsley said those who complained of not receiving a text may not have been meant to receive one because of their locations.

Acting Premier Peter Ryan defended the system, but still ordered an investigation of specific complaints.

"I consider the system at large worked well," Mr Ryan said.

"The vast majority of people concerned, as I understand it at the meeting, did receive an alert."

Mr Lapsley confirmed to the Herald Sun that an investigation of the CFA's website performance during the fire would be carried out after more complaints it was not working properly as the fires approached.

Mr Lapsley admitted the website might have slowed down, but denied there were any systemic flaws with the warning system.

"We know investing in the warning system is as critical as buying trucks and helicopters, and we will continue to monitor the website's performance," he said.

"But research shows people need to have more than one source of warning information."

Among the eight homes lost in the Chepstowe fire was the historic horse-breeding property Carngham station.

The fire was believed to have been caused by sparks from a truck or ute driving through a paddock.

Since last Thursday blazes have destroyed 9000ha of bushland in Victoria. Insurers estimate the bill will be around $9 million.

Farmers have lost up to 1000 head of livestock.

The CFA has renewed calls for farmers to delay all harvesting and slashing.

Other fires that began in the last 48 hours may have more sinister causes. Police are investigating six.

The most serious, which police are treating as suspicious, was a fast-moving grass fire in Wallan.

For a nerve-racking hour yesterday the blaze was moving towards homes, but firefighters threw two helicopters and 20 tankers into fighting it and stopped the blaze in its tracks.

A police spokesman urged the public to report any suspicions of fires being deliberately lit.

"The message from police is simple: if you've seen something or know something, then say something.

"There are serious consequences to bushfire arson.

"It can have a heavy impact on our environment, destroy people's homes and businesses, and can cause serious injury and tragic loss of life. Enforcement is key; however, we also need help from local communities."