In accordance with the Article 109 of the Act on electronic communications of the Republic of Croatia:
“Operators of public communication networks and publicly available electronic communication services are obliged to retain data on electronic communications (data necessary for monitoring and determining the source of communication, data necessary to determine the destination of the communication, - data necessary to determine the date, time and duration of the communication, data necessary to determine the type of communication, data necessary to determine the user's communication equipment or equipment that is considered to be the user's communication equipment, data necessary to determine the location of mobile communication equipment) for the purpose of enabling the investigation, detection and prosecution of criminal offenses in accordance with a special law in the field of criminal procedure and for the purpose protection of defence and national security in accordance with special laws in the field of defence and national security.
The operators referred to in paragraph 1 of this article are obliged to retain the data referred to in paragraph 1 of this article for a period of twelve months from the date of communication, regardless of the provisions of Article 102, paragraphs 1 and 2 of this Act.”
For the purpose of preservation of electronic evidence applicable provision is Article 29 para 1 of the European Convention on cybercrime:
“Party may request another Party to order or otherwise obtain the expeditious preservation of data stored by means of a computer system, located within the territory of that other Party and in respect of which the requesting Party intends to submit a request for mutual assistance for the search or similar access, seizure or similar securing, or disclosure of the data.
Upon receiving the request from another Party, the requested Party shall take all appropriate measures to preserve expeditiously the specified data in accordance with its domestic law.
Any preservation effected in response to the request referred to in paragraph 1 shall be for a period not less than sixty days, in order to enable the requesting Party to submit a request for the search or similar access, seizure or similar securing, or disclosure of the data. Following the receipt of such a request, the data shall continue to be preserved pending a decision on that request.”
For the purpose of provision of electronic evidence the following instruments shall be applied:
- Directive on the European Investigation Order in criminal matters
- the applicable international agreements (European Convention on Cybercrime )
- rule of reciprocity