1. In order to fulfil their duties under this Regulation, the competent authorities shall have all the supervisory and investigatory powers that are necessary for the exercise of their functions. They shall exercise their powers in any of the following ways:

(a) directly;

(b) in collaboration with other authorities;

(c) by application to the competent judicial authorities.

2. In order to fulfil their duties under this Regulation, the competent authorities shall, in accordance with national law, have the power:

(a) to gain access to any document in any form and to receive or take a copy thereof;

(b) to require information from any natural or legal person and if necessary to summon and question a natural or legal person with a view to obtaining information;

(c) to carry out on-site inspections with or without prior announcement;

(d) to require existing telephone and existing data traffic records;

(e) to require the cessation of any practice that is contrary to the provisions in this Regulation;

(f) to require the freezing and/or the sequestration of assets.