Home-made explosives and weapons are among the items uncovered by bomb disposal experts during an exhaustive search of the Derrinallum blast site, police have revealed.
The mammoth clean-up effort, about to enter its fourth week, will continue until the Hamilton Highway property can be declared safe.
Heavy machinery will be used in the next few days to dismantle the wrecked buildings which still litter the site.
The Australian Federal Police and Australian Defence Force are helping with the search for evidence on the 70-hectare farm.
A one-kilometre exclusion zone remains in place around the property as police continue to man 24-hour road blocks.
The highway has been closed since Friday, April 11 in the hours before Glenn Sanders, 48, triggered a series of explosions, injuring two policemen and killing himself.
The blasts came at the end of a seven-hour siege when police negotiators unsuccessfully attempted to get Sanders to remove a vest containing explosives that he had taken to wearing.
Forensic examinations have revealed human remains, recovered from the property several days after the blasts, belong to Sanders.
Acting Inspector Paul Ross said the operation’s progress was being reviewed each day but he was still not in a position to say if the highway might be re-opened to traffic in “days or weeks”.
“Our priority is the safety of the public and the people working on site,” Acting Inspector Ross said. “The Derrinallum community has been fantastic. It’s amazing the support we’ve got.”
Acting Superintendent Ross said the location of the property close to the highway and the timing of the blasts, just prior to Easter and the Warrnambool May Racing Carnival, had both worked against nearby towns which relied on passing motorists for a lot of their trade.
“It is a huge impact for them and we really appreciate their tolerant attitude.
“We’re mindful of the inconvenience we’re putting them through.”
He said the cost of the clean-up was substantial, but much of it was in the form of police wages and officers had to paid regardless.
“I can’t give you a figure. We’re not looking at a financial spreadsheet. It will have to be audited at the end and all accounted for.
“I’m not saying it’s millions of dollars, but these things are expensive.”
Homicide detectives working on the case are urging anyone with information about Sanders or people who have any historic or current photographs of his property to contact Crime Stoppers on 1800 333 000.