The company and directors may be fined substantial sums-see this section
79K Liability of directors of bodies corporate
If a body corporate is convicted of an offence against this Part, every director of the body corporate also commits the offence and is liable to the same penalty if it is proved that—
(a)the act or omission that constituted the offence took place with his or her express or implied authority; and
(b)he or she failed to take all reasonable steps to prevent or stop that act, or remedy that omission.
And this section
79U Offence to cause or require driver to breach maximum gross weight limits
Every person commits an offence, and is liable on conviction to a fine not exceeding $25,000, who, by act or omission, directly or indirectly causes or requires (whether or not the sole cause) a driver to operate a vehicle or combination of vehicles in breach of the applicable maximum gross weight limits for that vehicle or combination of vehicles if that person knew, or should have known, that the breach would, or would be likely to, occur.
This could be a criminal charge if this was a concealment for fraudulent purposes and possibly have a jail sentence. As an office worker you are unlikely to be involved unless you actively assisted in the overstatement