Two men arrested as part of national manhunt for top 20 fugitives

Police have arrested two of Australia's top 20 fugitives just days after the launch of Operation Roam, a nationwide blitz to find wanted criminals.

Andrew John Bell, 64, was arrested by an off-duty police officer in Adelaide on Tuesday and will be extradited to Victoria.

He was wanted on warrants related to deception offences worth $100,000, assaults and thefts in Maryborough, Victoria.

Scott John Heron was wanted in relation to an alleged sexual assault in Shepparton, Victoria.

He was arrested earlier this week.

Peter Price, the deputy chairman of Crime Stoppers Australia, said it was a great result.

"It's a fantastic example of Crime Stoppers, the media and the public working together to create a safer community," he said.

People are asked to visit the Crime Stoppers website to see if they recognise anyone, and to report the information if they do.

There are 18 other men being sought by police, including Stuart Pearce from South Australia, who is wanted for questioning over the alleged murders of his wife and three children at Parafield Gardens in South Australia in 1991.

There is a $1 million reward on offer from the South Australian Government for information leading to the arrest of the person who committed the murders.

Mr Price said Operation Roam would continue for another week-and-a-half and they were confident of making more arrests.