In relation to a solicitor, I would suggest you contact the Law Institute of Victoria and they will be able to provide you with names solicitors the practice in employment law/workers compensation that are close to you.
The Law Institute website is as follows:
If there are no solicitors in your local area, then they will suggest solicitors that are closest to you.
There are many solicitors that are accredited specialists in this area who could assist you and hopefully get resolved quickly.
The only recourse you have, against an employee who has allegedly stolen items is to contact the police and report the missing items for the police to investigate.
On the employment side it is gross misconduct, and the employer can summarily dismissed without any ramifications.
The recommendation by fellow worker, does not mean that that fellow worker can been held responsible for the actions of the employee.
I may have had no knowledge that the employee would steal.
But the matter should be reported to the police as it is a criminal offence and the law punishes employees who steal from their employer much harder than ordinary theft.
Is there anything else I can assist you with?