Artikel 19

1. The requesting and the requested Parties may agree to assist one another in the conduct of investigations into crime by officers acting under covert or false identity (covert investigations).
2. The decision on the request is taken in each individual case by the competent authorities of the requested Party with due regard to its national law and procedures. The duration of the covert investigation, the detailed conditions, and the legal status of the officers concerned during covert investigations shall be agreed between the Parties with due regard to their national law and procedures.
3. Covert investigations shall take place in accordance with the national law and procedures of the Party on the territory of which the covert investigation takes place. The Parties involved shall co-operate to ensure that the covert investigation is prepared and supervised and to make arrangements for the security of the officers acting under covert or false identity.
4. Parties shall at the time of signature or when depositing their instrument of ratification, acceptance, approval or accession, by means of a declaration addressed to the Secretary General of the Council of Europe, indicate the authorities that are competent for the purposes of paragraph 2 of this article. They subsequently may, at any time and in the same manner, change the terms of their declaration.