Article 20. Special investigative techniques 1. If permitted by the basic principles of its domestic legal system, each State Party shall, within its possibilities and under the conditions prescribed by its domestic law, take the necessary measures to allow for the appropriate use of controlled delivery and, where it deems appropriate, for the use of other special investigative techniques, such as electronic or other forms of surveillance and undercover operations, by its competent authorities in its territory for the purpose of effectively combating organized crime. 2. For the purpose of investigating the offences covered by this Convention, States Parties are encouraged to conclude, when necessary, appropriate bilateral or multilateral agreements or arrangements for using such special investigative techniques in the context of cooperation at the international level. Such agreements or arrangements shall be concluded and implemented in full compliance with the principle of sovereign equality of States and shall be carried out strictly in accordance with the terms of those agreements or arrangements. 3. In the absence of an agreement or arrangement as set forth in paragraph 2 of this article, decisions to use such special investigative techniques at the international level shall be made on a case-by-case basis and may, when necessary, take into consideration financial arrangements and understandings with respect to the exercise of jurisdiction by the States Parties concerned. 4. Decisions to use controlled delivery at the international level may, with the consent of the States Parties concerned, include methods such as intercepting and allowing the goods to continue intact or be removed or replaced in whole or in part. Article 21. Transfer of criminal proceedings States Parties shall consider the possibility of transferring to one another proceedings for the prosecution of an offence covered by this Convention in cases where such transfer is considered to be in the interests of the proper administration of justice, in particular in cases where several jurisdictions are involved, with a view to concentrating the prosecution. Article 22. Establishment of criminal record Each State Party may adopt such legislative or other measures as may be necessary to take into consideration, under such terms as and for the purpose 26