Article 397 of Civil Code

1 - If a person other than the debtor pays the creditor part of his claim and is subrogated to him in respect thereof, the creditor shall not be prejudiced by that subrogation and shall have priority over the person who paid him in recovering the remainder of his claim, unless an agreement provides otherwise. 2 - If another person is subrogated to the creditor in respect of the remainder of his claim, the person last subrogated and the person previously subrogated shall each have recourse to the extent of what is due to him, and shall share proportionately as creditors.