Victoria Police is now offering a $1 million reward for information leading to the arrest of fugitive Dezi Freeman, who is accused of killing two police officers in August.

Mr Freeman has been at large for 12 days, after a team of police officers executed a search warrant relating to historical sex offences at his property near Porepunkah in Victoria’s north-east.

Police allege the 56-year-old shot and killed two police officers and injured a third before leaving the property on foot and armed with multiple weapons.

The reward is the largest in Victorian history for facilitating an arrest. Other $1 million rewards have previously been offered in the state, but only in the case of information leading to a conviction.

Aerial shot of home in bush

For more than a week, police search teams have combed the countryside in the Victorian Alps for Dezi Freeman. (ABC News: Kyle Harley)

Homicide Squad Detective Inspector Dean Thomas said the reward reflected police’s determination to find Mr Freeman.

“This figure recognises the seriousness of this violent offending and our commitment to locating Freeman as soon as possible so that he is no longer a risk to the broader community,” he said.

“Our aim in offering this reward is that it will lead someone out there, who may not have been willing to come forward until this time, to contact police.

“There is no doubt that up to a million dollars is a life-changing amount of money for anyone and has the potential to completely change their circumstances.”

Low cloud hovers between pine trees in the foreground and a snow covered mountain behind under blue sky.

Police say the rough terrain has complicated and, at times, slowed the search operation. (ABC News)

Inspector Thomas said police believed the manhunt would only come to a resolution through the assistance of the public.

More than 450 police officers are searching for Mr Freeman in the mountainous terrain near Porepunkah, where temperatures dipped below freezing on Saturday.

There have been no confirmed sightings of Mr Freeman since the day of the shooting.

Multiple theories are being considered by police, including that Mr Freeman is being assisted by someone, is alone in the bush, or is already dead. 

He was last seen wearing dark green (khaki) tracksuit pants, a dark green rain jacket, brown Blundstone boots and reading glasses.

Anyone with any information about Freeman’s whereabouts is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at CrimeStoppers.