There are hopes that the lure of big money will help solve a cold case, as it has done in Australia.
Two-year-old Amber-Lee Cruickshank vanished from a home near the southern reaches of Lake Wakatipu in 1992.
Police have put up a $100,000 reward for any information, about what may have happened to her.
Support After Murder spokesperson Peter Wolfe told Mike Hosking a million dollar reward has been instrumental in solving three Australian cold cases.
He says in one case money was able to bring forward an alleged murderer's ex-wife.
Wolfe says money can, and does work, to solve crimes.
"In Australia there are 24 cases with a million dollar reward on offer, and so far three have resulted in the arrest of a suspect."