The States Parties undertake to include such offences as extraditable offences in every extradition treaty to be concluded between them. 2. If a State Party which makes extradition conditional on the existence of a treaty receives a request for extradition from another State Party with which it has not extradition treaty, it may consider this Convention as the legal basis for extradition in respect of such offences. Extradition shall be subject to the other conditions provided by the law of the requested State. 3. States Parties which do not make extradition conditional on the existence of a treaty shall recognize such offences as extraditable offences between themselves subject to the conditions provided by the law of the requested State. 4. Such offences shall be treated, for the purpose of extradition between States Parties, as if they had been committed not only in the place in which they occurred but also in the territories of the States required to establish their jurisdiction in accordance with article 5, paragraph 1. Article 9 1. States Parties shall afford to one another the greatest measure of assistance in connection with criminal proceedings brought in respect of any of the offences referred to in Article 4, including the supply of all evidence at their disposal necessary for the proceedings. 2. States Parties shall carry out their obligations under paragraph 1 of this article in conformity with any treaties on mutual judicial assistance that may exist between them. Article 11 Each State party shall keep under systematic review interrogation rules, instructions, methods and practices as well as arrangements for the custody and treatment of person subjected to any form of arrest, detention or imprisonment in any territory under its jurisdiction, with a view to preventing any cases of torture. Article 12 Each State party shall ensure that its competent authorities proceed to a prompt and impartial investigation, whenever there is reasonable ground to believe that an act of torture has been committed in any terretory under its jurisdiction. Article 13 Each State party shall ensure that any individual who alleges that he has been subjected to torture in any territory under its jurisdiction has the right to complain 66