La. Revenue and Taxation § 47:2162
The tax collector or tax assessor for the political subdivision, or any other person acting on behalf of the political subdivision whose duties are to assess or collect ad valorem taxes for the political subdivision, shall not buy, either directly or indirectly, any property or tax sale title sold or offered for sale for ad valorem taxes imposed by that political subdivision. The sale shall be subject to an action for nullity except that the violation of this Section shall not be a cause for annulling the sale if the property or tax sale title has been sold by the violator, his successor, or assigns to a person who purchased the property in good faith by onerous title. In addition to any other penalties provided by law for violation of this Section, the violator shall disgorge any profits he has made, either directly or indirectly, to the tax debtor.
La. Revenue and Taxation § 47:2162