Reglamento del sector inmobiliario
All property in Spain must be registered in the "Registro de Propiedad" or Land Registry. This is public information and is freely available provide you have the details. The basic document is called a "nota simple" (land registry extract). This will show name of the registered owner, if there are any liens, mortgages or debts registered against the property.
It will also show full details of the size of a plot of land, m2 of the property etc., and indeed if the property actually exists. Sometimes the reality is more m2 than that registered, an extension or addition which the vendors did not legalize etc.
Only the person or the judicial body shown on the land registry documentation may sell the property concerned, unless a notarised power of attorney has been given to a third party.
All transactions pertaining to the transfer of a property must be registered in the Land Registry. It is not sufficient to simply go to the notary office, the transactions must be duly registered afterwards and the official taxes due paid on the said transactions.
All purchases and sales of property take place in front of a notary, and due to money laundering regulations the process must be completely transparent. Bags of cash and brown envelopes are a thing of the past. The full purchase price must be declared and all of it accounted for in front of the notary. Banks have to provide certificates of funds passing via their accounts.
The notary checks the entire process is correct and notifies the land registry the same day that a transaction has taken place.