Tax authority decision to reject civil restitution claim is void due to lack of tax legal relationship basis.

The Supreme Court declared the tax chamber's administrative decision void for lacking legal grounds to adjudicate a civil restitution claim. The taxpayer voluntarily paid tax debts assumed by a privatized company, but the tax authority refused the refund, arguing it was a tax matter. The court ruled that since no tax legal relationship existed between the parties, the dispute must be resolved as a civil matter under the Civil Code, rendering the administrative decision inadmissible.