I couldn't find anything about this on AMDRH, I don't doubt it at all Duck, anyway will just have to keep an eye out for any news on the subject.
Anyway here's a good link that mentions a bit about theft by finding, you don't have to hand stuff in to the police but should for anything quite valuable. If a large sum of say cash or gold bullion is found you would be mad not to hand it in.
"In New South Wales it is punishable by up to 5 years imprisonment, home detention, community service and good behaviour bonds. Offenders may also have to make reparations to the victim.
For theft by finding to be proved, the prosecution must negate the following:
the goods were abandoned;
and that the accused did not believe that the owner could be found.
If the person accused of the crime honestly believed that the property was abandoned or that the owner cannot be found, they are not guilty."
http://www.sydneycriminallawyers.co...d-you-do-if-you-find-a-large-amount-of-money/