Lawsuit seeking a declaration of nullity of an expert examination conducted in the proceedings of an action for early production of evidence for the assessment of environmental damages. Subsequent arbitration agreement submitting to the arbitrator the resolution of a dispute taking into account the result of the aforementioned expert evidence. Given that the matter was not adjudicated in arbitration proceedings and was in fact prior to their commencement, it is appropriate for the nullity of the expert examination to be sought before the courts. Nullity of the agreement to arbitrate, which, in turn, must be assessed first by the arbitrator: