-- only an authorized police office executing warrant can do such thing .. under no circumstance a member of public can record this way and its very clear in law in simple words a penalty could be prison upto 5 years for such thing and can complicate matters further if harassment, mental trauma ,defamation blackmail is involved.
Firstly, this thread has been inactive for almost 2 years.
Second, "only an authorized police office[r] executing warrant can do such thing .. under no circumstance a member of public can record this way" is incorrect. There are circumstances where a private conversation can be recorded without the knowledge or consent of "all" parties to the conversation, but it does need to be authorized by at least "one" of the parties - see s7(3)(b) of the NSW Surveillance Devices Act 2007. Note that this varies from state to state - Victoria for example, does not have any such exception.
In short, in NSW you can record (or authorize someone else to record) a private conversation that you are a party to
1. for the purpose of protecting your legal interests, or
2. to simply have a record of what occurred for your own reference.
In the case #2 however, you can not communicate the recording or it's contents to anyone other than the original parties to the conversation. The use of illegally obtained recordings is covered by s11 of the Act.
In regards to evidence, as Rod pointed out, the Evidence Act generally prohibits the use of illegally obtained evidence, however courts do have discretion to allow it in the interest of fair justice.
It should also be pointed out that in the OP's case, it appears that the recordings were made with a mobile phone in the workplace. In such a case, it is possible that the conversation wouldn't qualify as a "private conversation" to begin with, because there could be reasonable grounds to believe that it could be overheard. This depends on the circumstances - for example, were they all in same office or area, or was the guy recording holding his phone up to a closed door (eavesdropping)?
The first example is unlikely to qualify as a private conversation, but the second example almost certainly would every time. It comes down to the definition of "private conversation", which in laymans terms, is where the parties
intend the conversation to be private between themselves
AND have a
reasonable expectation that the conversation would not be overheard.
