1. The competent authorities shall be given all supervisory and investigatory powers that are necessary for the exercise of their functions. Such powers shall be exercised:

(a) directly;

(b) in collaboration with other authorities;

(c) under the responsibility of the competent authorities, by delegation to entities to which tasks have been delegated; or

(d) by application to the competent judicial authorities.

2. Under paragraph 1, competent authorities shall have the power, at least, to:

(a) access any document in any form and receive a copy thereof;

(b) require any person to provide information and, if necessary, to summon and question a person with a view to obtaining information;

(c) carry out on-site inspections;

(d) require:

(i) in so far as permitted by national law, existing data traffic records held by a telecommunications operator, where there is a reasonable suspicion of an infringement and where such records may be relevant to an investigation into infringements of this Directive;