Reverse lookup phone directory

How do people get hold of this?

My tenants are clearly poor money managers and have run up a lot of debts. I have the phone still connected at my old house, redirected here as we have an ad in the yellow pages at that number so it is kind of necessary. So at least once a week I get a call from some 'business people' (clearly debt collectors) looking for X and Y at my old address, and they have got the number from a 'public database'. I am assuming they got the address from the bond lodgement database, or there's no other way to connect the tenants to that house.

It would also be nice to stop the calls that aren't for me, but the redirection expires in May anyway. Just annoying I get charged for these redirected long distance calls.
From this page:

It is reported that Sensis® will provide reverse searches to government agencies and other companies at their discretion.

Online reverse phone number searches may still be available online, however these are usually run as underground sites, and require password access. These also rely upon outdated data formerly found in CDs.

It is unlikely that we will see openly available reverse phone number searches available in Australia any time soon, due to restrictions on the use of IPND data. The Integrated Public Number Database (IPND) lists all Australian telephone numbers, and policy states that the data may not be used to provide a reverse search directory.

The people calling me are obviously one of those "agencies". It does sound like something debt collectors would have access to. Still damn annoying, the number should come back as a redirected one owned by someone NOT living at that address.
that link does work - just tried it...

that is a new one - I haven't seen it before. Greypages actually sold out to reverseonline which is now mirus

same scenario though, you have to pay for it...they use to offer 5 free searches if you signed up (didn't need to pay) - not sure if that is still the case though.

very hard to get reverse numbers - there was a CD you could buy with all Australian phone numbers on it, but it hasn't been updated for many years as legislation slowed that down...privacy act etc. Those companies would still have a copy of that CD and operate off that.