Police officers of a foreign state referred to in Article 40 of the Schengen Convention have a right to continue surveillance or technical surveillance of a person in the territory of Finland, initiated in the police officer's country for the purpose of investigating an offence. A further precondition is that Finnish police officers are not immediately able to continue surveillance or technical surveillance in Finland. Technical devises, which the Finnish police are authorized to use, may be used in the surveillance. A report on the measure shall be submitted to the district police within whose geographical area of operation surveillance, or most of it, was conducted. Customs officers of Member States applying the provisions of the Convention on Mutual Assistance and Cooperation between Customs Administrations may carry out cross-border operations pursuant to the Convention.