We study two different scenarios in which an external perturber can truncate the trans-Neptunian cometary population and we give plausibility arguments regarding both of them. First we study the perturbations induced in the Edgeworth-Kuiper Belt (EKB) by a stellar encounter. We also investigate the effects of a planetoid with semimajor axis at about 60 AU orbiting embedded in the primordial EKB. Arguments regarding the origin of such an object in the framework of our current understanding of the origin of the outer Solar System are given, as well as ranges for the magnitude and proper motion of the this hypothetical object. In this case, the mass and orbital orbital parameters of the planetoid that results in an EKB distribution as observed would compromise the stability of the Plutinos. Our results suggest that for both scenarios to reassemble the present observed distribution the edge of the EKB should roughly coincide with outer limit of the solid phase of the primordial Solar Nebular is discussed.