Generally speaking, Spanish law stipulates that the burden of proof should fall on the claimant (Art.217.2 of the Spanish Civil Procedure Act, Law 1/2000).
However, in certain cases the burden of proof is reversed, that is, it falls on the defendant.
Therefore, in the case provided for in Article 61.2 of the Patents Act (Law 11/1986), if the object of a patent is a procedure for producing new products or substances, it is assumed, unless proven otherwise, that all products and substances with the same characteristics have been obtained by means of the patented procedure. This means that the defendant will have to prove that the product has been obtained by means of a procedure different from the patented procedure.
