1. Competent authorities shall be given all supervisory and investigatory powers that are necessary for the exercise of their functions. Within the limits provided for in their national legal frameworks they shall exercise such powers:
(a) directly; or
(b) in collaboration with other authorities; or
(c) under their responsibility by delegation to entities to which tasks have been delegated according to Article 48(2); or
(d) by application to the competent judicial authorities.
2. The powers referred to in paragraph 1 shall be exercised in conformity with national law and shall include, at least, the rights to:
(a) have access to any document in any form whatsoever and to receive a copy of it;
(b) demand information from any person and if necessary to summon and question a person with a view to obtaining information;
(c) carry out on-site inspections;
(d) require existing telephone and existing data traffic records;
(e) require the cessation of any practice that is contrary to the