''I'm going to put it to them, because I reckon someone would come forward straight away,'' he said.
He strongly believed a reward would convince someone with information to contact police.
It comes as information released to the Otago Daily Times shows police have offered just two rewards for information in the South in the past decade.
One of those is the case of missing toddler Amber-Leigh Cruickshank, who was last seen on October 17, 1992, at a Cornwall St property in Kingston, at the southern end of Lake Wakatipu.
On April 13 police announced they were offering a $100,000 reward for information or evidence leading to the identity and conviction of anyone responsible for the 2-year-old's disappearance.
At the start of this month, Detective Inspector Stu Harvey said more than 70 calls had been received from people offering information.
The offer of a reward will remain in place until October 13.
The reward money will be funded through the police budget.
The other is the cold case disappearance of Dunedin woman Tuitania Barclay.
Barclay was last seen at her Wakari home on September 17, 2002.
In 2014, police offered a $50,000 reward for information about her suspected homicide.
No money was paid out in relation to that case, police confirmed.
Criminologist Greg Newbold said police rewards could be extremely effective tools.
''Those rewards, especially when they're substantial, which they tend to be, can be very effective in getting people to come forward and divulge information,'' he said.
There was the potential for issues, however.
For example, a teenage Teina Pora confessed to the 1992 murder of Susan Burdett because he wanted the $50,000 reward.
His murder conviction was later overturned.
Generally, Newbold said, the rewards tended to draw people out.
