South Australian police have posted $1 million rewards for a string of unsolved cases in which children were murdered or went missing.
Police say they hope the initiative, which increases some rewards from $200,000, will encourage people with "intimate" knowledge of cases to come forward with vital information.
They say breakthroughs in investigations will also help bring peace to the families of the victims.
The cases involve the murder or disappearance and presumed murder of 18 children including the infamous disappearance of the three Beaumont children in 1966.
Other cases include the disappearance of Joanne Ratcliffe and Kirste Gordon from Adelaide Oval in 1973 and a number of deaths sometimes referred to as "the Family Murders" and thought to involve a group of men who kidnapped, drugged, sexually abused and tortured their victims.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
One of those was 14-year-old Peter Stogneff, whose remains were found in 1982 at a property on Middle Beach at Two Wells, north of Adelaide, almost 10 months after he disappeared.
In August 1981, the teenager went missing after arranging to meet his cousin in Adelaide's Rundle Mall.
His cousin did not go into the city, so it cannot be confirmed whether the boy went into the city after leaving his suburban Hope Valley home.
In June the following year a property owner was clearing land at Two Wells when he found Peter's skeletal remains.
