In my opinion the POA has paid the owner the sale consideration amount as per the registered sale deed, hence the owner's claim for having sold the property at a higher value, without any evidence but only on a presumption or imaginary thought will not be legally maintainable.
If the sale of property was executed at the government rate then it cannot be considered as a deceitful act hence the revenue department may not entertain any such complaint.
Without documentary evidence the commissioner of police also may not entertain any complaint .
If there is proof to prove that the POA agent has accumulated Auden wealth and not paid taxes then a complaint for tax evasion can be made with documentary evidences to prove the allegations.
Unless you have clinching evidence to establish your allegations your efforts in this regard will be a futile exercise.