Been in a similar situation once before, agree with needing to check on the award or EBA or other industrial tool in place. From what you are saying about paying 41 standard hours and other variables, sounds as though the employees may be getting paid above award rates signifigantly to avoid the overtime rates (which is pretty standard after 40 hours maximum in most cases).
However, who gave you the advice you could withhold the pay? If it is legal advice and you have it in writing, go ahead and test it but be prepared to do an 'out of cycle' payment a few days after the regular pay date.
Before you do this though, make sure the following procedures are in place to protect yourself:
1. Make it known what the payroll cut off is, and make sure it is communicated to all staff and managers. Most office based environments this could be a quick email each pay cycle. Advise in the communication what the consequences are if the cut off is missed, ie will be held over for payment in the following week. (this is also useful for when you need to bring the cut off forward, to meet processing requirements due to public holidays etc)
2. Set you cut off time to leave you half an hour or so to follow up on any missing timesheets with managers and employees if required. Very important as I have had a case where the employee was in hospital and the manager failed to notify
HR or payroll. To aid in this, ensure your system can run a simple report showing all active employees on that particular payroll, and check the timesheets received off against the list.
3. Process the pays for all timesheets received.
4. Anyone complains about not getting a pay, direct them back to the previous communication. Ensure the managers are aware of this as well as they will usually try to get you to reverse time and get the paid ASAP.
End of the day, you work in
HR, not a creche. People need to be responsible for their own actions.